Isopropyl isocyanate → N-(5-tert-Butyl-1,2-oxazol-3-yl)-N'-propan-2-ylurea

Participants

Reaction Steps

7.5 g of 1-methylethyl isocyanate was added to a stirred mixture of 6.2 g of 1A and 75 ml of tetrahydrofuran at room temperature, then the mixture was stirred at reflux temperature for 24 hours, when an additional 7.5 g of 1-methylethyl isocyanate was added and the mixture was stirred at reflux temperature for 24 hours. The mixture was concentrated to dryness to give a syrup. On standing overnight at room temperature, a solid formed. The solid was recrystallized from ether/hexane to give 1-(1-methylethyl)-3-(5-(1,1-dimethylethyl)-isoxazol-3-yl)urea (4A), as an off-white solid, m.p.: 135°-138° C.

Provenance & Evidence