Prepn. of vincadifformine of formula (I) comprises (a) reacting a tetrahydro-beta-carboline of formula (II) with benzoyl chloride, (b) reacting with \-1 reducing agent, (c) chlorinating with tert.-butyl hypochlorite in the presence of triethylamine, (d) reacting with dialkyl malonate salt under reflux and opt. N-alkylating (e) partially decarboxylating, (f) hydrogenating, and (g) reacting with functionalised aldehyde to form an enammonium intermediate e.g. a halo- or epoxy-aldehyde. In the formulae R1 and R2 are each H, OH, acyloxy, carbamate, alkoxy, alkyl or halo, R3-5 are each H or 1-7C alkyl and A is opt satd. 1-7C alkyl chain opt. substd. by 1-7C alkyl, OH and/or hydroxyalkyl. (I) are intermediates for psychotropic vincamino derivs some of the cpds. have CNS activity.
Total synthesis of vincadifformine derivs.