A Novel Synthesis of o-Methoxy-p-Bis-(2-Chloroethyl)-Amino-Phenylalanine

In the previous paper it was reported that o-methoxy-p-bis-(2-chloroethyl)-aminophenylalanine (I, designated as 3P) exhibited marked inhibition against sarcoma 180, Guerin's carcinoma, Walker's carcinoma, Ehrlish ascites carcinoma, Spindle cell sarcoma and Yoshida ascites carcinoma, and its toxicity was somewhat lower than that of sarcolysin. Clinical studist showed that it possessed pronounced inhibiting action against some neoplastic diseases. For the purpose of simplifying the method of preparation, a novel synthesis of I has now been developed. When ethyl o-methoxy-p-bis-(2-hydroxyethyl)-amino-benzyl-formamido-malonate(Ⅱ)was chlorinated with thionyl chloride or phosphorus oxychloride, the product Ⅲ was an oilysubstance which was subjected to hydrolysis with hydrochloric acid to form I, but with poor yield. In this investigation, the chlorination was carried out by employing phosphorus pentachloride in dichloromethane and thus crystalline Ⅲ was obtained, from which I was obtained with satisfactory yield. In this communication, the synthesis of I starting with m-amino-anisole (IV) was also described. Compound IV was condensed with ethylene oxide in dilute acetic acid to give m-bis-(2-hydroxyethyl)-amino-anisole (V) which was then converted to o-methoxy-pbis-(2-chloroethyl)-amino-benzaldehyde (VI)by phosphorus oxychloride and dimethyl formamide. By condensation of compound VI with hippuric acid, 4-o-methoxy-p-bis(2-chloroethyl)-amino-phenylene-2-oxazolone-5 (VII) was obtained. The azlactone VII was subjected to alcoholysis on treatment with alcoholic potassium hydroxide to form methyl a-benzoylamido-o-methoxy-p-bis-(2-chloroethyl)-amino-cinnamate (VIII). Reductionof the latter by means of zinc dust or catalytic hydrogenation in the presence of palladium black gave N~a-benzoyl-o-methoxy-p-bis-(2-chloroethyl)-amino-phenylalanine methyl ester (IX), from which I was obtained on further hydrolysis. When compound IX was subiected to partial hydrolysis, there was obtained N~a-benzoyl-o-methoxy-p-bis-(2-chloroethyl)amino-phenylalanine hydrochloride (X). By treating the latter with ethanol or methanol o-methoxy-p-bis-(2-chloroethyl)-amino-phenylalanine ethyl ester (Ⅺ) or methyl ester (Ⅸ) was formed.