| 摘要 |
Intermediates represented by the general formula (I) and being useful in the synthesis of vinblastines: [wherein R1, R2, R3, and R4 are each independentl y H, lower alkyl, lower alkoxy, halogeno, lower perfluoroalkyl, lower alkylthi o, hydroxyl, amino, mono- or di-(alkyl or acyl)amino, or lower alkyl- or aryl- sulfonyloxy; R5 is H, lower alkyl, or substituted or unsubstituted aryl; R6 is alkyl having not more than four carbon atoms; R7 is substituted or unsubstituted aryl; R8 is substituted or unsubstituted aryl or lower alkyl; and R9 is acyl or trialkylsilyl]. A process for preparation of the above intermediates which comprises the synthesis of indole by radical cyclization of a thioanilide and the formation of a 11-membered cycle by intramolecular alkylation of 2-nitrobenzenesulfonamide and by which the reactions can proce ed under mild conditions and high yield can be attained.
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