Triethylamine → n-[6-(2,5-Dimethyl-2h-pyrazol-3-yl)-2,4-dioxo-7-trifluoromethyl-1,4-dihydro-2h-quinazolin-3-yl]-methanesulfonamide

Participants

Reaction Steps

To a solution of 2-amino-5-(2,5-dimethyl-2H-pyrazol-3-yl)-4-trifluoromethyl-benzoic acid methyl ester (610 mg, 1.95 mmol) in DCM (20 mL) containing Et3N (1.1 mL, 4 equiv) was added (CCl3O)2CO (294 mg, 0.5 equiv) portionwise. The mixture was stirred at r.t. for 2 h and was the solvent was removed in vacuo. The resulting paste was dissolved in THF (20 mL) and CH3SO2NHNH2 (214 mg, 1 equiv) was added. The mixture was stirred at r.t. for 1 h and an aqueous solution of NaOH (1N, 1.95 mL, 1 equiv) was added. The mixture was stirred at r.t. for 2 h. The mixture was then poured into water and the aqueous phase was extracted with AcOEt. The aqueous layer was acidified to pH 3 by addition of 2N aq HCl and then extracted with AcOEt. The organic phases were combined, dried (Na2SO4) and concentrated in vacuo to afford a brown syrup. The crude product was purified by flash chromatography (EtOAc/hexanes (25:75) to EtOAc) to furnish N-[6-(2,5-dimethyl-2H-pyrazol-3-yl)-2,4-dioxo-7-trifluoromethyl-1,4-dihydro-2H-quinazolin-3-yl]-methanesulfonamide (213 mg, 26%) as a white powder. (ESI-MS: m/z 418.4 [M+H]+, rt 4.30 min) 1H-NMR (DMSO-d6, 400 MHz) 12.1 (s, 1H), 10.38 (s, 1H), 7.91 (s, 1H), 7.64 (s, 1H), 6.08 (s, 1H), 3.47 (s, 3H), 3.16 (s, 3H), 2.17 (s, 3H).

Provenance & Evidence