Isocyanate → 1-(4-Chloro-3-(trifluoromethyl)phenyl)-3-(4-(2-oxo-1,2-dihydro pyrido[2,3-b]pyrazin-8-yloxy)phenyl)urea

Participants

Reaction Steps

Method F1 (one pot deprotection of Boc and coupling with isocyanate): Tert-butyl 4-(2-oxo-1,2-dihydropyrido[2,3-b]pyrazin-8-yloxy)phenylcarbamate (0.240 g, 0.67 mmol) is dissolved in trifluoroacetic acid (2 ml) and the solution is stirred at room temperature under Argon atmosphere for 2 h. The solvent is evaporated under reduced pressure and the resulting dark oil is dissolved in THF (3 ml) and triethylamine (1 ml). 1-chloro-4-isocyanato-2-(trifluoromethyl)benzene (0.180 g, 0.80 mmol) is added in one portion, and the solution was stirred overnight at 45 C under Ar atmosphere. The solution is then cooled and evaporated and the crude was crystallised from dichloromethane and diethyl ether to afford the title compound (15 mg, 5% yield) as a brown solid.

Provenance & Evidence