反应详情

To a solution of ethyl 2-phenyl-5-aminothiazole-4-carboxylate (116 mg, 1.0 eq) in dichloromethane (3 ml) at −78° C. was added chlorosulfonyl isocyanate (0.06 ml, 1.3 eq) dropwise (Redman et al J. (2000) Org. Lett. 2:2061-2063). The reaction was slowly warmed to room temperature and stirred for 40 minutes. The reaction was concentrated. To the residue was added 6N HCl (2.5 ml) and mixture was heated to 100° C. for 20 minutes. Reaction mixture was allowed to cool down to room temperature, and was neutralized with saturated aq. NaHCO3. Solid was collected by filtration to yield ethyl 2-phenyl-5-ureidothiazole-4-carboxylate 63 as a beige solid which was used in the next reaction without further purification.

1. concentrationThe reaction was concentrated
2. additionTo the residue was added 6N HCl (2.5 ml) and mixture
3. temperaturewas heated to 100° C. for 20 minutes
4. customReaction mixture
5. temperatureto cool down to room temperature
6. filtrationSolid was collected by filtration