Fremgangsmate for fremstilling av combretastatiner

Preparation of combrestatins (I) by a Wittig condensation of (3,4,5-trimethoxybenzyl) triphenyl phosphonium bromide or chloride with 3-nitro-4-methoxy benzaldehyde, or of 3,4,5-trimethoxy benzaldehyde with a (4-methoxy-3-nitrobenzyl) triphenyl phosphonium salt, followed by reduction of the nitro group on the product in the presence of iron. Preparation of combrestatins (I) by a Wittig condensation of (3,4,5-trimethoxybenzyl) triphenyl phosphonium bromide or chloride with 3-nitro-4-methoxy benzaldehyde, or of 3,4,5-trimethoxy benzaldehyde with a (4-methoxy-3-nitrobenzyl) triphenyl phosphonium salt, followed by reduction of the nitro group on the product in the presence of iron. [Image] A' : an amino group. Independent claims are included for (1) the process as described but in which the nitro group in the starting material is replaced by an amino group; (2) preparation of 2-amino-3-hydroxy-N-{2-methoxy-5-[2-(3,4,5-trimethoxy-phenyl)-vinyl]-phenyl}-propionamide hydrochloride salt of formula (IV) by reacting (I; A = NH 2) with a protected cyclic derivative of serine of formula (IIb), to give an intermediate (III) followed by removal of the protecting group PG; (3) intermediates of formula (III). [Image] [Image] PG : a protecting group such as tert. butoxycarbonyl, benzyloxy carbonyl, or 9-fluorenylmethyloxy carbonyl. ACTIVITY : Cytostatic. MECHANISM OF ACTION : Not given in source material.