反应详情

A solution of 4.2 g. (0.02 mole) of DL-α-isocyanato-2-thiopheneacetic acid, ethyl ester and 1.2 g. (0.02 mole) of N,N-dimethylhydrazine in 80 ml. of methylene chloride is stirred overnight. The solution is concentrated and to the syrupy residue are added 10 ml. of 2N sodium hydroxide solution. After stirring for 30 minutes, a clear yellow solution results. By the addition of acetic acid, 3.9 g. of α-dimethylhydrazinocarbonylamino-2-thiopheneacetic acid are obtained, m.p. 208°-210°.

1. concentrationThe solution is concentrated and to the syrupy residue
2. additionare added 10 ml
3. customa clear yellow solution results