O-haloacetyl-n-carbobenzoxyserines

The invention comprises O-haloacetyl-N-carbobenzoxyserine compounds of the general formula (wherein X represents a halogen atom, B represents hydrogen, an alkali metal or one equivalent of an alkaline-earth metal, and R1 represents a benzyl radical, which may be unsubstituted or substituted, e.g. by halogen atoms or alkyl, alkoxy, amino or nitro radicals in the nucleus and/or by alkyl or phenyl radicals in the side chain), and the preparation thereof by reacting an N-carbobenzoxyserine with a haloacetyl halide or haloacetic anhydride, followed, if desired, by treatment of the product with an alkali or alkaline-earth metal hydroxide, carbonate, bicarbonate, oxide, alkoxide or amide. The main reaction is advantageously carried out below 125 DEG C. in a non-hydroxylated organic solvent, and may be catalysed by concentrated sulphuric acid or by a tertiary amine, the temperature in the latter case preferably being between 0 DEG and 25 DEG C. Examples describe the interaction of: (1) bromoacetyl bromide and N-carbobenzoxy-dl-serine in benzene and ethyl acetate in the presence or absence of triethylamine; (2) chloroacetic anhydride and N-carbobenzoxy-dl-serine in ethyl acetate in the presence of concentrated sulphuric acid; (3) bromoacetyl bromide and N-carbobenzoxy-l-serine in ethyl acetate in the presence of triethylamine; (4) chloroacetyl chloride and N-carbobenzoxy-l-serine in ethyl acetate in the presence of pyridine. Reference is also made to iodoacetyl compounds.