Synthesis of 1,3-Disubstituted Symmetrical/Unsymmetrical Ureas via Cs₂CO₃-Catalyzed Transamination of Ethylene Carbonate and Primary Amines

Abstract

Cs₂CO₃-catalyzed transamination of primary amines and ethylene carbonate proceeds to form 1,3-disubstituted symmetrical/unsymmetrical ureas in excellent yields. The effect of different reaction parameters such as influences of bases, temperature, and reaction time were investigated for the title reaction.

Keywords:

• Cesium carbonate
• 1,3-disubstituted urea
• ethylene carbonate
• primary amine
• transamination

ACKNOWLEDGMENT

The financial support from the Technical Education Quality Improvement Program (TEQIP), Government of India, is acknowledged.

Notes

^a Yields refer to isolated pure products characterized by IR, GC-MS, and ¹H NMR.

Notes. Reaction conditions: butyl amine: 20 mmol, ethylene carbonate: 10 mmol; temp.: 90 °C, base: 0.2 mmol, and time: 20 min.

^a Yields refer to isolated pure products characterized by IR, GC-MS, and ¹H NMR.

Notes. Reaction conditions: amine: 20 mmol, ethylene carbonate: 10 mmol, Cs₂CO₃: 0.2 mmol.

^a Yields are based on GC analysis.

Notes. Reaction conditions: ethylene carbonate (10 mmol) was reacted with amine (1; 10 mmol) at 70 °C for 1 h, and then the formed 2-hydroxycarbamate was reacted with amine (4; 10 mmol) at 100 °C for 30 min using 0.2 mmol Cs₂CO₃.