Yamasaki Ryu, Honjo Yutaka, Ito Ai, Fukuda Kazuo, Okamoto Iwao
Showa Pharmaceutical University.
Chem Pharm Bull (Tokyo). 2018;66(9):880-884. doi: 10.1248/cpb.c18-00394.
We have discovered a spontaneous reaction of N,O-diaryl carbamates to afford symmetrical N,N'-diarylureas. Optimization of the conditions indicated that N,N-dimethylformamide (DMF) was the best solvent and triethylamine (EtN) was the best additive for this transformation. The reaction requires the presence of aryl groups on the nitrogen and oxygen atoms of carbamates. Substrates bearing an electron-donating methoxy group on either of the aryl groups reacted slowly under these conditions.
我们发现N，O-二芳基氨基甲酸酯会自发反应生成对称的N，N'-二芳基脲。条件优化表明，N，N-二甲基甲酰胺（DMF）是该转化反应的最佳溶剂，三乙胺（EtN）是最佳添加剂。该反应要求氨基甲酸酯的氮原子和氧原子上均存在芳基。在这些条件下，芳基上带有供电子甲氧基的底物反应缓慢。
