Author: claimsbot

1. An input buffer, comprising:
a main input transistor pair that receives a voltage input;
a tail current source; and
a squeezable tail current source circuit coupled to the main input transistor pair and to the tail current source, the squeezable tail current source circuit including a single-ended self-biased folded feedback loop,
wherein the main input transistor pair, the tail current source, and the squeezable tail current source circuit are configured such that current through the main input transistor pair is maintained as the voltage input varies.
2. The input buffer of claim 1, wherein the folded feedback loop comprises:
a folding transistor; and
a biasing current source that biases the folding transistor.
3. The input buffer of claim 2, wherein the squeezable tail current source circuit further includes:
a replica transistor pair coupled to the tail current source and the folding transistor that replicates the main input transistor pair and receives the voltage input;
a bias transistor coupled to the replica transistor pair, the folding transistor, and the biasing current source; and
a tail transistor pair coupled to the bias transistor, the folding transistor, and the biasing current source,
wherein the biasing current source and the folding transistor isolate the bias transistor and the tail transistor pair from a drain voltage of the replica transistor pair.
4. The input buffer of claim 3, wherein current through the tail transistor pair and the bias transistor is squeezed as the voltage input to the main input transistor pair is decreased, thereby increasing a gate voltage of the bias transistor, and thereby causing current through both the replica transistor pair and the main input transistor pair to remain nearly constant.
5. The input buffer of claim 3, wherein an input to the replica transistor pair is scaled independently to meet different bandwidth requirements for settling.
6. The input buffer of claim 3, wherein the main input transistor pair, the replica transistor pair, the tail transistor pair, and the bias transistor are NMOS transistors.
7. The input buffer of claim 3, wherein the main input transistor pair, the replica transistor pair, the tail transistor pair, and the bias transistor are PMOS transistors.
8. The input buffer of claim 2, wherein the folding transistor is an NMOS transistor.
9. The input buffer of claim 2, wherein the folding transistor is a PMOS transistor.
10. A differential input buffer, comprising:
a first main input transistor pair that receives a first voltage input;
a second main input transistor pair that receives a second voltage input;
a first tail current source;
a second tail current source;
a first squeezable tail current source circuit coupled to the first main input transistor pair and to the first tail current source, the first squeezable tail current source circuit including a first single-ended self-biased folded feedback loop;
a second squeezable tail current source circuit coupled to the second main input transistor pair and to the second tail current source, the second squeezable tail current source circuit including a second single-ended self-biased folded feedback loop,
wherein the first main input transistor pair, the first tail current source, and the first squeezable tail current source circuit are configured such that current through the first main input transistor pair is maintained as the first voltage input varies; and
wherein the second main input transistor pair, the second tail current source, and the second squeezable tail current source circuit are configured such that current through the second main input transistor pair is maintained as the second voltage input varies.
11. The differential input buffer of claim 10, wherein the first folded feedback loop comprises:
a first folding transistor; and
a first biasing current source that biases the first folding transistor.
12. The differential input buffer of claim 11, wherein the first squeezable tail current source circuit further includes:
a replica transistor pair coupled to the first tail current source and the first folding transistor that replicates the first main input transistor pair and receives the first voltage input;
a bias transistor coupled to the replica transistor pair, the first folding transistor, and the first biasing current source; and
a tail transistor pair coupled to the bias transistor, the first folding transistor, and the first biasing current source,
wherein the first biasing current source and the first folding transistor isolate the bias transistor and the tail transistor pair from a drain voltage of the replica transistor pair.
13. The differential input buffer of claim 12, wherein current through the tail transistor pair and the bias transistor is squeezed as the first voltage input to the first main input transistor pair is decreased, thereby increasing a gate voltage of the bias transistor, and thereby causing current through both the replica transistor pair and the first main input transistor pair to remain nearly constant.
14. The differential input buffer of claim 12, wherein the first main input transistor pair, the replica transistor pair, the tail transistor pair, and the bias transistor are NMOS transistors.
15. The differential input buffer of claim 12, wherein the first main input transistor pair, the replica transistor pair, the tail transistor pair, and the bias transistor are PMOS transistors.
16. The differential input buffer of claim 11, wherein the first folding transistor is an NMOS transistor.
17. The differential input buffer of claim 11, wherein the first folding transistor is a PMOS transistor.
18. The differential input buffer of claim 10, wherein the second folded feedback loop comprises:
a second folding transistor; and
a second biasing current source that biases the second folding transistor.
19. The differential input buffer of claim 18, wherein the second squeezable tail current source circuit further includes:
a replica transistor pair coupled to the second tail current source and the second folding transistor that replicates the second main input transistor pair and receives the second voltage input;
a bias transistor coupled to the replica transistor pair, the second folding transistor, and the second biasing current source; and
a tail transistor pair coupled to the bias transistor, the second folding transistor, and the second biasing current source,
wherein the second biasing current source and the second folding transistor isolate the bias transistor and the tail transistor pair from a drain voltage of the replica transistor pair.
20. The differential input buffer of claim 19, wherein current through the tail transistor pair and the bias transistor is squeezed as the second voltage input to the second main input transistor pair is decreased, thereby increasing a gate voltage of the bias transistor, and thereby causing current through both the replica transistor pair and the second main input transistor pair to remain nearly constant.
21. The differential input buffer of claim 19, wherein the second main input transistor pair, the replica transistor pair, the tail transistor pair, and the bias transistor are NMOS transistors.
22. The differential input buffer of claim 19, wherein the second main input transistor pair, the replica transistor pair, the tail transistor pair, and the bias transistor are PMOS transistors.
23. The differential input buffer of claim 18, wherein the second folding transistor is an NMOS transistor.
24. The differential input buffer of claim 18, wherein the second folding transistor is a PMOS transistor.
25. The differential input buffer of claim 10, further comprising:
a first stage having an input coupled to the first and second main input transistor pairs and having an output;
a second stage having an input coupled to the first stage output and having an output; and
an output coupled to the second stage output.
26. A method of maintaining a constant current through a main input transistor pair of a differential amplifier while maintaining high linearity, the method comprising:
providing a voltage input to the main input transistor pair;
mirroring a tail current to that of the current through the main input transistor pair by using a squeezable tail current source configured to isolate a bias transistor and a first transistor pair of the squeezable tail current source from a drain voltage of a second transistor pair of the squeezable tail current source, thereby causing the second transistor pair and the main input transistor pair to have a common drain bias; and
squeezing the tail current as the voltage input is decreased, thereby increasing a gate voltage of the bias transistor and allowing current through the main input differential pair to remain nearly constant.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. An ORing element for use in a power supply, the ORing element comprising:
a field effect transistor (FET) for electrical connection between an output of the power supply and a bus;
a first bi-polar transistor, wherein an emitter of the first bi-polar transistor is electrically connected to a source of the FET, and wherein a collector of the first bi-polar transistor is electrically connected to a gate of the FET; and
a second bi-polar transistor, wherein an emitter of the second bi-polar transistor is electrically connected to a base of the second bi-polar transistor and a base of the first bi-polar transistor, and wherein a collector of the second bi-polar transistor is electrically connected to a drain of the FET.
2. The ORing element of claim 1, wherein the collector of the first bi-polar transistor is electrically connected to a first bias current.
3. The ORing element of claim 1, wherein the emitter of the second bi-polar transistor is electrically connected to a second bias current.
4. The ORing element of claim 1, wherein the first bi-polar transistor and the second bi-polar transistor are contained in a single package.
5. The ORing element of claim 4, wherein the single package is a 6-pin SOT-23 package.
6. A power system comprising:
a first power supply module;
a common power bus; and
an ORing element connected between the first power supply module and the common power bus, wherein the ORing element comprises:
a field effect transistor (FET) electrically connected between the first power supply module and the common power bus;
a first bi-polar transistor, wherein an emitter of the first bi-polar transistor is electrically connected to a source of the FET, and wherein a collector of the first bi-polar transistor is electrically connected to a gate of the FET; and
a second bi-polar transistor, wherein an emitter of the second bi-polar transistor is electrically connected to a base of the second bi-polar transistor and a base of the first bi-polar transistor, and wherein a collector of the second bi-polar transistor is electrically connected to a drain of the FET.
7. The power system of claim 6, wherein the collector of the first bi-polar transistor is electrically connected to a first bias current.
8. The power system of claim 6, wherein the emitter of the second bi-polar transistor is electrically connected to a second bias current.
9. The power system of claim 6, wherein the first bi-polar transistor and the second bi-polar transistor are contained in a single package.
10. The power system of claim 9, wherein the single package is a 6-pin SOT-23 package.
11. The power system of claim 6, further comprising a second power supply module;
and a second ORing element connected between the second power supply module and the common power bus.

1. A liquid crystal display, comprising:
a light guide plate having a light-emitting plane on one end surface;
a light source arranged on a side surface of the light guide plate; and
a liquid crystal panel arranged opposite the light-emitting plane;
wherein deflection patterns are formed on a surface opposite the light-emitting plane,
the defection patterns are arranged so that two independent components on the surface opposite the light-emitting plane become random,
in a certain region on the surface opposite the light-emitting plane, when an average number of the deflection patterns included in each region opposite each pixel of the liquid crystal panel is designated by \u03bcn and a standard deviation is designated by \u03c3n, their ratio satisfies the following relationship:
0<\u03c3n\u03bcn\u22660.154,

light from the light source introduced into the light guide plate is deflected towards the light-emitting plane by the deflection patterns so as to be emitted from the light-emitting plane,
the liquid crystal panel is illuminated by the light emitted from the light-emitting plane.
2. A liquid crystal display, comprising:
a light guide plate having a light-emitting plane on one end surface;
a light source arranged on a side surface of the light guide plate; and
a liquid crystal panel arranged opposite the light-emitting plane,
wherein deflection patterns are formed on a surface opposite the light-emitting plane,
the deflection patterns are arranged so that two independent components on the surface opposite the light-emitting plane are random,
in a certain square region having a side with length of K on the surface opposite the light-emitting plane, when the number of the deflection patterns included in the corresponding square region is designated by M, a ratio of a pixel pitch p of the liquid crystal panel to an average pattern gap defined by:
Samp_A=K(\u221aM)

satisfies the following relationship:
Samp_Ap\u22660.28,

light from the light source introduced into the light guide plate is deflected towards the light-emitting plane by the deflection patterns so as to be emitted from the light-emitting plane,
the liquid crystal panel is illuminated by the light emitted from the light-emitting plane.
3. A liquid crystal display, comprising:
a light guide plate having a light-emitting plane on one end surface;
a point light source arranged on a side surface of the light guide plate; and
a liquid crystal panel arranged opposite the light-emitting plane,
wherein deflection patterns are formed on a surface opposite the light-emitting plane,
the deflection patterns are arranged so that two independent components on the surface opposite the light-emitting plane are random,
in the case where a projection area of the deflection patterns to the light-emitting plane is designated by S, a distance between the light source and the deflection pattern is designated by Rp and a thickness of the light guide plate in positions of the deflection patterns is designate by d, in a certain region on the surface opposite the light-emitting plane, when an average value obtained by adding S(Rp\xd7d) of all the deflection patterns included in all the regions opposite the pixels of the liquid crystal panel is designated by \u03bc\u03b1 and a standard deviation is designated by \u03c3\u03b1, their ratio satisfies the following relationship:
0<\u03c3\u03b1\u03bc\u03b1\u22660.154,

light from the light source introduced into the light guide plate is deflected towards the light-emitting plane by the deflection patterns so as to be emitted from the light-emitting plane,
the liquid crystal panel is illuminated by the light emitted from the light-emitting plane.
4. The liquid crystal display according to claim 1, wherein a minimum gap between the deflection patterns is larger in a direction parallel with a direction of the light source than that in a direction perpendicular to the direction of the light source.
5. The liquid crystal display according to claim 2, wherein a minimum gap between the deflection patterns is larger in a direction parallel with a direction of the light source than that in a direction perpendicular to the direction of the light source.
6. The liquid crystal display according to claim 3, wherein a minimum gap between the deflection patterns is larger in a direction parallel with a direction of the light source than that in a direction perpendicular to the direction of the light source.
7. A surface light source device, comprising:
a light guide plate having a light-emitting plane on one end surface; and
a light source arranged on a side surface of the light guide plate;
wherein deflection patterns are formed on a surface opposite the light-emitting plane,
the defection patterns are arranged so that two independent components on the surface opposite the light-emitting plane become random,
in a certain region on the surface opposite the light-emitting plane, when an average number of the deflection patterns included in each pixel corresponding region is designated by \u03bcn and a standard deviation is designated by \u03c3n, their ratio satisfies the following relationship:
0<\u03c3n\u03bcn\u22660.154,

light from the light source introduced into the light guide plate is deflected towards the light-emitting plane by the deflection patterns so as to be emitted from the light-emitting plane.
8. A surface light source device, comprising:
a light guide plate having a light-emitting plane on one end surface; and
a light source arranged on a side surface of the light guide plate;
wherein deflection patterns are formed on a surface opposite the light-emitting plane,
the deflection patterns are arranged so that two independent components on the surface opposite the light-emitting plane are random,
in a certain square region having a side with length of K on the surface opposite the light-emitting plane, when the number of the deflection patterns included in the corresponding square region is designated by M, a ratio of a pixel pitch p of a pixel corresponding region to an average pattern gap defined by:
Samp_A=K(\u221aM)

satisfies the following relationship:
Samp_Ap\u22660.28,

light from the light source introduced into the light guide plate is deflected towards the light-emitting plane by the deflection patterns so as to be emitted from the light-emitting plane.
9. A surface light source device, comprising:
a light guide plate having a light-emitting plane on one end surface; and
a point light source arranged on a side surface of the light guide plate;
wherein deflection patterns are formed on a surface opposite the light-emitting plane,
the deflection patterns are arranged so that two independent components on the surface opposite the light-emitting plane are random,
in the case where a projection area of the deflection patterns to the light-emitting plane is designated by S, a distance between the light source and the deflection pattern is designated by Rp and a thickness of the light guide plate in positions of the deflection patterns is designate by d, in a certain region on the surface opposite the light-emitting plane, when an average value obtained by adding S(Rp\xd7d) of all the deflection patterns included in all the pixel corresponding regions of the liquid crystal panel is designated by \u03bc\u03b1 and a standard deviation is designated by \u03c3\u03b1, their ratio satisfies the following relationship:
0<\u03c3\u03b1\u03bc\u03b1\u22660.154,

light from the light source introduced into the light guide plate is deflected towards the light-emitting plane by the deflection patterns so as to be emitted from the light-emitting plane.

The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.

1. A method of treating diabetes, which method involves treating a patient in need thereof with a therapeutically effective amount of a compound of formula (I):
in which:
Ra is hydrogen, halogen, C(1-3)alkyl, C(1-3)alkoxy, hydroxyC(1-3)alkyl, C(1-3)alkylthio, C(1-3)alkylsulphinyl, aminoC(1-3)alkyl, mono- or di-C(1-3)alkylaminoC(1-3)alkyl, C(1-3)alkylcarbonylaminoC(1-3)alkyl, C(1-3)alkoxyC(1-3)alkylcarbonylaminoC(1-3)alkyl, C(1-3)alkylsulphonylaminoC(1-3)alkyl, C(1-3)alkylcarboxy, or C(1-3)alkylcarboxyC(1-3)alkyl;
Rb is hydrogen, halogen, C(1-3)alkyl, or hydroxyC(1-3)alkyl, with the proviso that Ra and Rb are not simultaneously each hydrogen; or
Ra and Rb together are (CH2)n where n is 3 or 4, to form, with the pyrimidine ring carbon atoms to which they are attached a fused 5- or 6-membered carbocyclic ring; or
Ra and Rb together with the pyrimidine ring carbon atoms to which they are attached form a fused benzo or heteroaryl ring unsubstituted or substituted by 1, 2, 3 or 4 substituents which may be the same or different selected from the group consisting of halogen, C(1-4)alkyl, cyano, C(1-4)alkoxy or C(1-4)alkylthio, and mono to perfluoro-C(1-4)alkyl);
Rc is hydrogen or C(1-3)alkyl;
R2 is an aryl or heteroaryl group, unsubstituted or substituted by 1, 2, 3 or 4 substituents which may be the same or different selected from the group consisting of C(1-18)alkyl, C(1-18)alkoxy)C(1-18)alkylthio, arylC(1-18)alkoxy, hydroxy, halogen, CN, COR6, carboxy, COOR6, NR6COR7, CONR8R9, SO2NR8R9, NR6SO2R7, NR8R9, mono to perfluoro-C(1-4)alkyl, mono to perfluoro-C(1-4)alkoxyaryl, and arylC(1-4)alkyl;
R3 is hydrogen, C(1-6)alkyl which may be unsubstituted or substituted by 1, 2 or 3 substituents selected from the group consisting of hydroxy, halogen, OR6, COR6, carboxy, COOR6, CONR8R9, NR8R9, NR8COR9, mono- or di-(hydroxyC(1-6)alkyl)amino and N-hydroxyC(1-6)alkyl-N\u2014C(1-6)alkylamino; or
R3 is Het-C(0-4)alkyl in which Het is a 5- to 7-membered heterocyclyl ring comprising N and optionally O or S, bonded through a carbon ring atom and in which N is unsubstituted or substituted by COR6, COOR6, CONR8R9, or C(1-6)alkyl unsubstituted or substituted by 1, 2 or 3 substituents selected from the group consisting of hydroxy, halogen, OR6, COR6, carboxy, COOR6, CONR8R9 and NR8R9;
R4 is an aryl or a heteroaryl ring unsubstituted or substituted by 1, 2, 3 or 4 substituents which may be the same or different selected from the group consisting of C(1-18)alkyl, C(1-18)alkoxy, C(1-18)alkylthio, arylC(1-18)alkoxy, hydroxy, halogen, CN, COR6, carboxy, COOR6, NR6COR7, CONR8R9, SO2NR8R9, NR6SO2R7, NR8R9, mono to perfluoro-C(1-4)alkyl and mono to perfluoro-C(1-4)alkoxy;
R5 is an aryl or heteroaryl ring which is unsubstituted or substituted by 1, 2, 3 or 4 substituents which may be the same or different selected from the group consisting of C(1-18)alkyl, C(1-18)alkoxy, C(1-18)alkylthio, arylC(1-18)alkoxy, hydroxy, halogen, CN, COR6, carboxy, COOR6, CONR8R9, NR6COR7, SO2NR8R9, NR6SO2R7, NR8R9, mono to perfluoro-C(1-4)alkyl and mono to perfluoro-C(1-4)alkoxy;
R6 and R7 are independently hydrogen or C(1-20)alkyl;
R8 and R9 may be the same or different and are selected from the group consisting of hydrogen and C(1-12)alkyl; or
R8 and R9 together with the nitrogen to which they are attached form a 5- to 7 membered ring optionally containing one or more further heteroatoms which are oxygen, nitrogen or sulphur, and is unsubstituted or substituted by one or two substituents selected from the group consisting of hydroxy, oxo, C(1-4)alkyl, C(1-4)alkylCO, aryl, and aralkyl; or
R8 and R9 may be the same or different and are selected from the group consisting of CH2R10 and CHR11CO2H, or a salt thereof;
R10 is COOH or a salt thereof, COOR12, CONR6R7, CN, CH2OH or CH2OR6;
R11 is an amino acid side chain;
R12 is C(1-4)alkyl or a pharmaceutically acceptable in vivo hydrolysable ester group;
n is 1 to 4;
X is O or S;
Y is (CH2)p(O)q in which p is 1, 2 or 3 and q is 0 or p is 2 or 3 and q is 1; and
Z is O or a bond;

or a pharmaceutically acceptable salt thereof.
2. A method as claimed in claim 1 in which Ra is chloro, bromo, methyl, ethyl, n-propyl, methoxy, hydroxymethyl, hydroxyethyl, methylthio, methylsulphinyl, aminoethyl, dimethylaminomethyl, acetylaminoethyl, 2-(methoxyacetamido)ethyl, mesylaminoethyl, ethylcarboxy, methanesulfonamidoethyl, (methoxyacetamido)ethyl or iso-propylcarboxymethyl.
3. A method as claimed in claim 1 in which Rb is hydrogen or methyl.
4. A method as claimed in claim 1 in which Ra and Rb together with the pyrimidine ring carbon atoms to which they are attached form a fused 5-membered carbocyclic ring or a fused benzo or heteroaryl ring selected from the group consisting of benzo, pyrido and thieno.
5. A method as claimed in claim 1 in which Rc is hydrogen or methyl.
6. A method as claimed in claim 1 in which X is S.
7. A method as claimed in claim 1 in which Y is CH2.
8. A method as claimed in claim 1 in which Z is a direct bond.
9. A method as claimed in claim 1 in which R2 is an aryl group, unsubstituted or substituted by 1, 2, 3 or 4 substituents which are the same or different and are selected from the group consisting of C(1-6)alkyl, C(1-6)alkoxy, C(1-6)alkylthio, hydroxy, halogen, CN, mono to perfluoro-C(1-4)alkyl, mono to perfluoro-C(1-4)alkoxyaryl, and arylC(1-4)alkyl.
10. A method as claimed in claim 1 in which R2 is phenyl, unsubstituted or substituted by halogen.
11. A method as claimed in claim 1 in which R2 is phenyl optionally substituted by one to three fluorine atoms.
12. A method as claimed in claim 1 in which R3 is C(1-3)alkyl substituted by a substituent which is NR8R9; or R3 is Het-C(0-2)alkyl in which Het is a 5- to 7-membered heterocyclyl ring comprising N and in which N is unsubstituted or substituted by C(1-6)alkyl.
13. A method as claimed in claim 1 in which R3 is 2-(diethylamino)ethyl.
14. A method as claimed in claim 1 in which R4 is phenyl.
15. A method as claimed in claim 1 in which R5 is phenyl substituted by trifluoromethyl.
16. A method as claimed in claim 1 in which R4 and R5 together form a 4-(4-trifluoromethylphenyl)phenyl moiety.
17. A method as claimed in claim 1, wherein the compound of formula (I) is a compound of the formula (IA):
in which:
Ra is hydrogen, halogen, C(1-3)alkyl, C(1-3)alkoxy, hydroxyC(1-3)alkyl, C(1-3)alkylthio, C(1-3)alkylsulphinyl, aminoC(1-3)alkyl, mono- or di-C(1 -3)alkylaminoC(1-3)alkyl, C(1-3)alkylcarbonylaminoC(1-3)alkyl, C(1-3)alkoxyC(1-3)alkylcarbonylaminoC(1-3)alkyl, C(1-3)alkylsulphonylaminoC(1-3)alkyl, C(1-3)alkylcarboxy, or C(1-3)alkylcarboxyC(1-3)alkyl;
Rb is hydrogen, halogen, C(1-3)alkyl, or hydroxyC(1-3)alkyl, with the proviso that Ra and Rb are not simultaneously each hydrogen; or
Ra and Rb together are (CH2)n where n is 3 or 4, to form, with the pyrimidine ring carbon atoms to which they are attached a fused 5- or 6-membered carbocyclic ring; or
Ra and Rb together with the pyrimidine ring carbon atoms to which they are attached form a fused benzo or heteroaryl ring unsubstituted or substituted by 1, 2, 3 or 4 substituents which may be the same or different selected from the group consisting of halogen, C(1-4)alkyl, cyano, C(1-4)alkoxy or C(1-4)alkylthio, and mono to perfluoro-C(1-4)alkyl);
Rc is hydrogen or C(1-3)alkyl;
R2 is an aryl or heteroaryl group, unsubstituted or substituted by 1, 2, 3 or 4 substituents which may be the same or different selected from the group consisting C(1-18)alkyl, C(1-18)alkoxy)C(1-18)alkylthio, arylC(1-18)alkoxy, hydroxy, halogen, CN, COR6, carboxy, COOR6, NR6COR7, CONR8R9, SO2NR8R9, NR6SO2R7, NR8R9, mono to perfluoro-C(1-4)alkyl, mono to perfluoro-C(1-4)alkoxyaryl, and arylC(1-4)alkyl;
R3 is hydrogen, C(1-6)alkyl which may be unsubstituted or substituted by 1, 2 or 3 substituents selected from the group consisting of hydroxy, halogen, OR6, COR6, carboxy, COOR6, CONR8R9, NR8R9, NR8COR9, mono- or di-(hydroxyC(1-6)alkyl)amino and N-hydroxyC(1-6)alkyl-N\u2014C(1-6)alkylamino; or
R3 is Het-C(0-4)alkyl in which Het is a 5- to 7-membered heterocyclyl ring comprising N and optionally O or S, bonded through a carbon ring atom and in which N is unsubstituted or substituted by COR6, COOR6, CONR8R9; or C(1-6)alkyl unsubstituted or substituted by 1, 2 or 3 substituents selected from the group consisting of hydroxy, halogen, OR6, COR6, carboxy, COOR6, CONR8R9 and NR8R9;
R4 is an aryl or a heteroaryl ring optionally substituted by 1, 2, 3 or 4 substituents which may be the same or different selected from the group consisting of C(1-18)alkyl, C(1-18)alkoxy, C(1-18)alkylthio, arylC(1-18)alkoxy, hydroxy, halogen, CN, COR6, carboxy, COOR6, NR6COR7, CONR8R9, SO2NR8R9, NR6SO2R7, NR8R9, mono to perfluoro-C(1-4)alkyl and mono to perfluoro-C(1-4)alkoxy;
R5 is an aryl or heteroaryl ring which is unsubstituted or substituted by 1, 2, 3 or 4 substituents which may be the same or different selected from the group consisting of C(1-18)alkyl, C(1-18)alkoxy, C(1-18)alkylthio, arylC(1-18)alkoxy, hydroxy, halogen, CN, COR6, carboxy, COOR6, CONR8R9, NR6COR7, SO2NR8R9, NR6SO2R7, NR8R9, mono to perfluoro-C(1-4)alkyl and mono to perfluoro-C(1-4)alkoxy;
R6 and R7 are independently hydrogen or C(1-20)alkyl;
R8 and R9 may be the same or different and are selected from the group consisting of hydrogen and C(1-12)alkyl; or
R8 and R9 together with the nitrogen to which they are attached form a 5- to 7 membered ring optionally containing one or more further heteroatoms which are oxygen, nitrogen or sulphur, and is unsubstituted or substituted by one or two substituents selected from the group consisting of hydroxy, oxo, C(1-4)alkyl, C(1-4)alkylCO, aryl, and aralkyl; or
R8 and R9 may be the same or different and are selected from the group consisting of CH2R10 and CHR11CO2H, or a salt thereof;
R10 is COOH or a salt thereof, COOR12, CONR6R7, CN, CH2OH or CH2OR6;
R11 is an amino acid side chain;
R12 is C(1-4)alkyl or a pharmaceutically acceptable in vivo hydrolysable ester group;
n is 1 to 4; and
X is O or S.
18. A method as claimed in claim 1, wherein the compound of formula (I) is a compound of formula (IB):
in which:
Ra and Rb together with the pyrimidine ring carbon atoms to which they are attached form a fused 5-membered carbocyclic ring;
R2CH2X is 4-fluorobenzylthio;
R3 is C(1-3)alkyl substituted by NR8R9; or
R3 is Het-C(0-2)alkyl in which Het is a 5- to 7-membered heterocyclyl ring comprising N and in which N is unsubstituted or substituted by C(1-6)alkyl;
R4 and R5 form a 4-(4-trifluoromethylphenyl)phenyl moiety;
R8 and R9 which may be the same or different are selected from the group consisting of hydrogen, or C(1-6)alkyl); and
X is S.
19. A method of treating diabetes, which method involves treating a patient in need thereof with a therapeutically effective amount of a compound which is:
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-ethylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrid-5-yl-methyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-ethylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrimid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-methyl-N-(2-(4-chlorophenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-(2-aminoethyl)pyrimidin-4-one;
1-(N-methyl-N-(2-(4-chlorophenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-(2-acetamidoethyl)pyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-chlorophenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-(dimethylaminomethyl)pyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-chlorophenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-methylpyrimidin-4-one;
1-(N-methyl-N-(2-(4-trifluoromethylphenyl)pyrid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-methylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-methylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrid-5-yl-methyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-methylpyrimidin-4-one
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-chlorophenyl)pyrimid-5-yl-methyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-methylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrimid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-methylpyrimidin-4-one;
(\xb1)-1-(N-(2-(diethylamino)ethyl)-N-(1-(4-(4-chlorophenyl)phenyl)ethyl)-aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-methylpyrimidin-4-one;
1-(N-(2-(1-piperidino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-methylpyrimidin-4-one;
1-(N-methyl-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-ethylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-chlorophenyl)benzyl)aminocarbonyl-methyl)-2-(4-fluorobenzyl)thio-5-ethylpyrimidin-4-one;
1-(N-methyl-N-(2-(4-trifluoromethylphenyl)pyrid-5-yl-methyl)-aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-ethylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-chlorophenyl)pyrimid-5-ylmethyl)-aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-ethylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrimid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-ethylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-chlorophenyl)benzyl)aminocarbonyl-methyl)-2-(4-fluorobenzyl)thio-5-propylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-propylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-ethoxycarbonylmethylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-isopropoxycarbonylmethylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-chlorophenyl)benzyl)aminocarbonyl-methyl)-2-(4-fluorobenzyl)thio-5-hydroxymethylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-hydroxymethylpyrimidin-4-one;
1-(N-methyl-N-(4-(4-chlorophenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-(2-hydroxyethyl)pyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-chlorophenyl)benzyl)aminocarbonyl-methyl)-2-(4-fluorobenzyl)thio-5-(2-hydroxyethyl)pyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-(2-hydroxyethyl)pyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-(2-hydroxyethyl)pyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-dimethylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-chlorophenyl)benzyl)aminocarbonyl-methyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-chlorophenyl)benzyl)aminocarbonyl-methyl)-2-(4-fluorobenzyl)thio-5,6-tetramethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-tetramethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-tetramethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-chloropyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-chlorophenyl)benzyl)aminocarbonyl-methyl)-2-(4-fluorobenzyl)thio-5-chloropyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-chloropyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-bromopyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-chlorophenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-bromopyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-methoxypyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-methoxypyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-ethoxypyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-ethoxypyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-methylthiopyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-methylthiopyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-methylsulfinylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-methylsulfinylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(2,3-difluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(3,4-difluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(2,3,4-trifluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(2-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-methyl-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(2-(1-piperidino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(3-(4-trifluoromethylphenoxy)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenoxy)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylbiphenyl-4-yl)propyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylbiphenyl-4-yl)propyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-ethylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylbiphenyl-4-yloxy)ethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-ethylpyrimidin-4-one;
1-(N-(1-ethylpiperidin-4-yl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(2-ethylamino-2-methylpropyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
N-(2-tert-butylaminoethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
N-(2-diethylaminoethyl)-2-2-(4-fluorobenzylthio)-4-oxo-4H-thieno3,2-dpyrimidin-1-yl-N-(4\u2032-trifluoromethylbiphenyl-4-ylmethyl)acetamide;
N-(2-diethylaminoethyl)-2-2-(4-fluorobenzylthio)-4-oxo-4 H-quinazolin-1-yl-N-(4\u2032-trifluoromethylbiphenyl-4-ylmethyl)acetamide;
ethyl-{2-{2-(4-fluorobenzylthio)-4-oxo-4,5,6,7-tetrahydrocyclopentapyrimidin-1-ylethanoyl}-4\u2032-trifluoromethylbiphenyl-4-ylmethyl)aminoethyl}carbamic acid tert-butyl ester;
1-(N-(1-methylpiperidin-4-yl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(1-isopropylpiperidin-4-yl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(1-(2-methoxyethyl)piperidin-4-yl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-(2-aminoethyl)pyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-(2-acetamidoethyl)pyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-(2-methanesulfonamidoethyl)pyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-(2-(methoxyacetamido)ethyl)pyrimidin-4-one; or
1-(N-(2-(ethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one; or
a pharmaceutically acceptable salt thereof.
20. A method as claimed in claim 19, wherein the method involves treating a patient in need thereof with a therapeutically effective amount of a compound which is:
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-ethylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5-ethylpyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one;
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one; or
1-(N-(2-(diethylamino)ethyl)-N-(2-(4-trifluoromethylphenyl)pyrimid-5-ylmethyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one; or

a pharmaceutically acceptable salt thereof.
21. A method of treating diabetes, which method involves treating a patient in need thereof with a therapeutically effective amount of 1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one, or a pharmaceutically acceptable salt thereof.
22. A method as claimed in claim 21, wherein the method involves treating a patient in need thereof with a therapeutically effective amount of 1-(N-(2-(diethylamino)ethyl)-N-(4-(4-trifluoromethylphenyl)benzyl)aminocarbonylmethyl)-2-(4-fluorobenzyl)thio-5,6-trimethylenepyrimidin-4-one.