| 摘要 |
New process for the production of (6S)-5,6,7,8-tetrahydrofolic acid or derivatives thereof starting from the corresponding (6S, 6R) racemic mixture. The procedure comprises in the steps of adding an organic acid to a non- alkaline suspension of (6S,6R)-5,6,7,8-tetrahydrofolic acid, up to a pH value in the range of 1 to 3; heating the suspension from 30~ to 80~C; cooling the suspension from 20~ to 60~C, with selective crystallization of the (6S)- isomer. The procedure gives the (6S)-isomer in high yields and with a high degree of stereoselectivity. It follows that the synthetic access to a large number of pharmacologically active stereoisomers of folic acid is simpler and more effective.
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