| 摘要 |
The invention relates to a method for the preparation of an enantiomerically pure imidazolyl compound of the general formula <CHEM> wherein: n is 0 or 1; m is 1 or 2; R1 is hydrogen, methyl or ethyl; and C* denotes a chiral centre; as well as its pharmaceutically acceptable acid addition salt; by a) adding a carboxylic acid in an optically active form to a solution of a racemic mixture of the above compound I, followed by separation of the crystallized acid addition salt of said mixture of enantiomers of compound I enriched in one enantiomer, from the mother liquor enriched in the other enantiomer b) when the crystallized acid addition salt is enriched in the undesired enantiomer, by then separating the mixture of enantiomers in the mother liquor from said optically active carboxylic acid, followed by addition of a racemic mixture of said carboxylic acid to a solution of the obtained mixture of isomers of I, and by separation of the crystallized acid addition salt of said mixture, enriched in the desired enantiomer, from the mother liquor, and (c) optionally recrystallizing the product until the desired enantiomeric purity is obtained, and by then (d) converting this acid-addition salt of the desired enantiomer to the desired enantiomerically pure imidazolyl compound of the general formula I or to its pharmaceutically acceptable acid addition salt, characterized in that pyroglutamic acid is used as said carboxylic acid. The invention further relates to a method of racemisation and to a new acid addition salt of this formula I compound and D-pyroglutamic acid. |
