A process for preparing 3- (amino) -crotonsaeuremethylester

The invention relates to a new process for preparing methyl 3-aminocrotonate by reacting methyl acetoacetate with ammonia, which comprises carrying out the reaction at a temperature of 35 to 70 DEG C in the presence of water. Methyl 3-aminocrotonate is an important intermediate in the pharmaceutical industry. The crotonate obtained by this process is free from side products, and no solvent is required in the process which is eminently useful for realization at an industrial scale.