| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject compound which has potent and long-acting vasodilative and antihypertensive activities, and useful for cure of hypertension by separating diastereomer as a free base or its optically inactive acid-added salt from a mixture of two kinds of optical isomers. SOLUTION: An optically active 1,4-dihydropyridine derivative is obtained by separating diastereomer as a free base or its optically inactive acid-added salt from a mixture of two kinds of optical isomers of the formula (R1 , R2 , and R3 are each independently a lower alkyl; A is a 1-10C straight-chain alkylene; Ar is hydroxyl, cyano, nitro, etc.; W is cyano, or a lower haloalkyl; *is an optically active center). In this case, the separation of the diastereomer is preferably fractional crystallization of optically active acid-added salt, e.g., fractional crystallization of hydrochloride, sulfate, oxalate, fumarate, etc. |
