ALANYLPROLINE DERIVATIVE AND ITS USE

NEW MATERIAL:Crystals of free dibenzylphosphoryl-alanyl-prolyl-proline. USE:Hypotensor. PREPARATION:Benzyl alcohol and phosphorus trichloride are allowed to act on dibenzylphosphoryl chloride dimethylaniline to form dibenzyl hydrogen phosphite, which is allowed to react with sulfuryl chloride, then combined with L-proline- benzyl ester hydrochloride, 1-hydroxybenzotriazole and N,N'-dimethylamino- propyl-ethylcarbodiimide to form N-t-butyloxycarbonyl-L-alanyl-L-proline benzyl ester. Then, hydrogen is passed through the product and L-proline benzyl ester hydrochloride is allowed to act on the product. Finally, the reaction mixture is worked up to form oily dibenzylphosphoryl-L-alanyl-L-proline benzyl ester, which is collected from the residue by alkali treatment followed by pH ajdustment with an acid.