Diisopropylethylamine → n-(6-Oxazol-5-yl-2,4-dioxo-7-trifluoromethyl-1,4-dihydro-2h-quinazolin-3-yl)-methanesulfonamide

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-amino-5-oxazol-5-yl-4-trifluoromethyl-benzoic acid methyl ester (248 mg, 0.866 mmol) and 4-chlorophenyl chloroformate (121 μL, 0.886 mmol) in dioxane (4 mL) was heated to 80° C. for 1 h. The reaction mixture was concentrated in vacuo. The crude residue was dissolved in dioxane (4 mL) and treated with CH3SO2NHNH2 (191 mg, 1.732 mmol) and i-Pr2NEt (454 μL, 2.60 mmol). After heating at 80° C. for 1 h, the reaction mixture was concentrated in vacuo. The residue was purified by two successive flash chromatographies (70 g of silica gel, 2% MeOH in DCM), then (20 g silica gel, DCM→MeOH in DCM (1% to 3%)) to give the title compound (65 mg) as an off-white powder. This solid was further purified by sonication in DCM to provide 24 mg of pure product. The filtrate was concentrated in vacuo and sonicated in Et2O to give a further 27.8 mg of title product, for a total of 51.8 mg (15%) of the title compound as an off-white powder. API-ES: m/z 408.0 [M+NH4]+, rt 2.89 min.

Provenance & Evidence