Processes for the preparation of combretastatins

摘要

Disclosed are processes for the preparation of combretastatins of general formula (I) in which A represents an amino group, comprising condensing a (3,4,5-trimethoxybenzyl)triphenylphosphonium salt with a 3-amino-4-methoxy benzaldehyde or condensing a (3-amino-4-methoxybenzyl)triphenylphosphonium salt with 3,4,5-trimethoxybenzaldehyde and reducing the nitro group in the presence of iron. Also disclosed is a process and intermediates for producing serine salts of formula (I) by way of reaction with a cyclic protected serine derivative of formula (IIb) to form an intermediate of formula (III) which is subsequently deprotected.