Patent ID: 7238802

Claim:
An intermediate for vinblastine synthesis represented by formula A, wherein, R 1 , R 2 , R 3 and R 4 are selected independently from the group consisting of H, lower alkyl group, lower alkoxy group, halogen, lower perfluoroakyl group, lower alkylthio group, hydroxy group, amino group, mono- or di-alkyl or acylamino group, lower alkyl or arylsulfonyloxy group, R 5 is H, or a lower alkyl group or a substituted or non-substituted aryl group, R 6 is an alkyl group of carbon number 4 or less, R 7 is a substituted or non-substituted aryl group, R 8 is a substituted or non-substituted aryl group or lower alkyl group and R 9 is an acyl group or trialkylsilyl group.