生物碱Bharatamine的光化学合成

Synthesis of Bharatamine via Photochemistry

以苯乙酸和３甲氧基４苄氧基苯乙胺（１）为原料，通过１苯亚甲基２甲酰基６甲氧基７苄氧基３，４二氢异喹啉（４）的光环合得原小檗碱型碘化物（５），再经四氢硼钠还原、脱苄基合成了ｂｈａｒａｔａｍｉｎｅ（７），总收率达３８５％．放射配体受体结合试验表明该生物碱对多巴胺Ⅰ亚型受体有较强的亲和力．

From phenylacetic acid and 3methoxy4benzyloxy phenethylamine,bharatamine(7),a natural racemic protoberberine alkaloid,was synthesized via photocyclization of 1benzylidene2formyl6methoxy7benzyloxy3,4dihydroisoquinoline(4),followed by reduction with NaBH 4 and debenzylation with hydrochloric acid.The overall yield amounted to 385%.The receptor binding assays showed that the affinity of bharatamine to D 1 receptros was higher than that of stepholidine,and vice versa to D 2 receptors.