0 Introduction 3-aminocrotonic acid methyl ester, also known as 3-aminocrotonic acid methyl ester, is an important pharmaceutical intermediates, widely used in nitrendipine, nisoldine, nicardipine, felodipine, etc. Several varieties of calcium antagonists in the synthesis of antihypertensive Methyl 3-aminocrotonate drugs horizon class .1-4 At present, reported in the literature synthesis of 3-aminocrotonic acid methyl ester methods are: First, excessive ammonium acetate as the ammonia source in methanol or acetic acid