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US 5,844,105 AGranted
Preparation of crystal form II of clarithromycin
AssigneeAbbott Laboratories
InventorsJih-Hua Liu, David A. Riley
Life of this patent
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Abstract
The present invention provides a process for the preparation of 6-O-methylerythromycin A Form II comprising converting erythromycin A to 6-O-methylerythromycin A and treating the 6-O-methylerythromycin A with a number of common organic solvents or mixtures of common organic solvents.
Claims16
A method of preparing 6-O-methylerythromycin A crystal form II comprising
- (a) converting erythromycin A to 6-O-methylerythromycin A;
- (b) treating the 6-O-methylerythromycin A prepared in step a with a solvent selected from the group consisting of
- (i) an alkanol of from 1 to 5 carbon atoms, provided said alkanol is not ethanol or isopropanol,
- (ii) a hydrocarbon of from 5 to 12 carbon atoms,
- (iii) a ketone of from 3 to 12 carbon atoms,
- (iv) a carboxylic ester of from 3 to 12 carbon atoms, provided said carboxylic ester is not isopropyl acetate,
- (v) an ether of from 4 to 10 carbon atoms,
- (vi) benzene,
- (vii) benzene substituted with one or more substituents selected from the group consisting of
- alkyl of from one to four carbon atoms,
- alkoxy of from one to four carbon atoms,
- nitro, and
- halogen,
- (viii) a polar aprotic solvent,
- (ix) a compound having the formula HNR.sup.1 R.sup.2 wherein R.sup.1 and R.sup.2 are independently selected from hydrogen and alkyl of one to four carbon atoms, provided that R.sup.1 and R.sup.2 are not both hydrogen,
- (x) water and a water miscible solvent selected from the group consisting of
- a water miscible organic solvent and
- a water miscible alkanol,
- (xi) methanol and a second solvent selected from the group consisting of
- a hydrocarbon of from 5 to 12 carbon atoms,
- an alkanol of from 2 to 5 carbon atoms,
- a ketone of from 3 to 12 carbon atoms,
- a carboxylic ester of from 3 to 12 carbon atoms,
- an ether of from 4 to 10 carbon atoms,
- benzene, and
- benzene substituted with one or more substituents selected from the group consisting of
- alkyl of from one to four carbon atoms,
- alkoxy of from one to four carbon atoms,
- nitro, and
- halogen, and
- (xii) a hydrocarbon of from 5 to 12 carbon atoms and a second solvent selected from the group consisting of
- a ketone of from 3 to 12 carbon atoms,
- a carboxylic ester of from 3 to 12 carbon atoms,
- an ether of from 4 to 10 carbon atoms,
- benzene,
- benzene substituted with one or more substituents selected from the group consisting of
- alkyl of from one to four carbon atoms,
- alkoxy of from one to four carbon atoms,
- nitro, and
- halogen, and
- a polar aprotic;
- and
- (c) isolating the 6-O-methylerythromycin A form II crystals.
40 more elements
Dependencies are inferred from the claim text.