1. A process for the preparation of a salt of citalopram comprising: (A) dissolving citalopram in a solvent selected from acetone, alcohol, or toluene or mixtures thereof and adding oxalic acid; (B) separating the precipitated citalopram oxalate; (C) suspending said citalopram oxalate in water and adding a base in an amount sufficient to liberate citalopram; (D) extracting the liberated citalopram with an organic solvent, isolating the organic phase and evaporating said solvent; optionally repeating steps (A) to (D), repeating steps (A) and (B) and subsequently; (E) suspending said citalopram oxalate in water and adding base to a pH 6 to 7; (F) adding a solvent selected from toluene, cyclohexane, n-hexane, n-heptane, isopropyl ether or xylene or mixtures thereof and isolating the aqueous phase; (G) adding base to said aqueous phase in an amount sufficient to liberate citalopram and extracting the liberated citalopram with an organic solvent, isolating the organic phase and evaporating said solvent; (H) dissolving said citalopram in an alcohol solvent, adding an acid and separating the precipitated citalopram salt.
2. A process for the separation of desmethyl citalopram from a crude mixture thereof with citalopram base comprising: (A) dissolving citalopram in a solvent selected from acetone, alcohol, or toluene or mixtures thereof and adding oxalic acid; (B) separating the precipitated citalopram oxalate; (C) suspending said citalopram oxalate in water and adding a base in an amount sufficient to liberate citalopram; (D) extracting the liberated citalopram with an organic solvent, isolating the organic phase and evaporating said solvent; optionally repeating steps (A) to (D).
3. A process for the separation of 5-chlorocitalopram and 5-bromocitalopram from a crude mixture of citalopram oxalate comprising: (E) suspending citalopram oxalate in water and adding base to a pH 6 to 7; (F) adding a solvent selected from toluene, cyclohexane, n-hexane, n-heptane, isopropyl ether or xylene or mixtures thereof and isolating the aqueous phase.
4. A process for the separation of 5-carboxyamide from a crude mixture of citalopram comprising: (H) dissolving citalopram in an alcohol solvent, adding an acid and separating the precipitated salt.
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 angiography system for examining an object of a patient, comprising:
a patient support table for supporting the patient;
a C-arm;
an x-ray emitter disposed at an end of the C-arm;
an x-ray image detector disposed at another end of the C-arm for recording an x-ray image of the object, wherein the object comprises details hiding each other in the x-ray images depending on an angulation of the C-arm;
a monitor that displays the x-ray image; and
a control unit configured to:
record a 3D dataset of the object registered to the C-arm,
detect a course of the object from the 3D dataset,
calculate an optimum angulation of the C-arm from the detected information, and
adjust the C-arm to the optimum angulation for recording the x-ray image.
2. The angiography system as claimed in claim 1, wherein the details in the x-ray images do not hide each other at the optimum angulation of the C-arm.
3. The angiography system as claimed in claim 1, wherein the optimum angulation of the C-arm lies at a right angle to a connecting axis of the details and lies at a right angle to a main axis of the object.
4. The angiography system as claimed in claim 1, wherein the control unit records a location of a main axis of the object and a fixed point on the object outside the main axis in the 3D dataset for detecting the course of the object.
5. The angiography system as claimed in claim 1, wherein the 3D dataset of the object comprises a pre-operative CT, MR angiography registered to the C-arm or an intra-operative rotation angiography showing soft tissue of the object.
6. The angiography system as claimed in claim 1, wherein the course of the object is determined by defining a center line of the object by a segmentation of the 3D dataset.
7. The angiography system as claimed in claim 1, wherein the object is a stent in an aorta.
8. The angiography system as claimed in claim 7, wherein the details are openings of the stent.
9. An angiographic examination method for examining an object of a patient by an angiography system, comprising:
recording a 3D dataset of the object registered to a C-arm of the angiography system by an imaging recording method;
determining a course of the object comprising a main axis by a control unit of the angiography system;
selecting a point on the object outside the main axis by the control unit;
selecting two other points at a distance from each other on the main axis of the object;
determining a plane in space formed by the point and the two other points;
calculating a perpendicular to the plane as an angulation of the C-arm by the control unit;
setting the C-arm to the calculated angulation by the control unit; and
recording an x-ray imagine of the object at the calculated angulation by the angiography system.
10. The angiographic examination method as claimed in claim 9, wherein the object is a stent in an aorta.
11. The angiographic examination method as claimed in claim 9, wherein the C-arm is set at the calculated angulation automatically or by pressing a button.
12. The angiographic examination method as claimed in claim 9, wherein the point selected on the object outside the main axis is a position of an opening of the object in space.
13. The angiographic examination method as claimed in claim 9, wherein the calculated angulation of the C-arm lies at a right angle to the main axis and lies at a right angle to a connecting axis between two openings of the object.
14. The angiographic examination method as claimed in claim 9, wherein the 3D dataset of the object is recorded by a pre-operative CT, MR angiography registered to the C-arm or an intra-operative rotation angiography showing soft tissue of the object.