3-取代-1,2,3,9-四氢-4H-咔唑-4-酮衍生物的合成

Synthesis of 3-Substitued-1,2,3,9-Tetrahydro-4H-Carbazol-4-One Derivatives

根据新型5-HT_3受体拮抗剂Ondansetron的结构特点,本文用2-烷基取代的苯并咪唑及苯并三唑代替原来结构中的咪唑环,合成了五个衍生物Ⅵ_(a-d)及Ⅶ。起始原料为环己酮,经Fischer吲哚合成反应、氧化、乙基化、Mannich反应,与盐酸成盐及缩合等反应合成了目的物。对其中的Mannich反应条件进行了改进,使其收率提高到57.8%。

On the basis of the structure of known highly selective 5-HT_3 antagonists, a series of 9-ethyl-3-benzimidazol (and benzotriazol)-1-yl-methyl-1,2,3,9-tetrahydro-4H-carbazol-4-one derivatives (Ⅵ_(a-d) and Ⅵ) were synthesized from 9-ethyl-1,2,3,9-tetrahydro-4H-carbazol- 4-one (Ⅲ) by Mannich reaction, salt forming reaction and condensation with appropriate benzimidazoles or benzotriazole. Compound Ⅲ was prepared from cyclohexanone through Fischer indole synthesis, oxidation and ethylation.