TFA dichloromethane water → 2-Methanesulfonyl-thieno[2,3-h]quinazoline-8-carboxylic acid

Participants

Reaction Steps

2-Methanesulfonyl-thieno[2,3-h]quinazoline-8-carboxylic acid tert-butyl ester (4.20 g, 11.52 mmol) was placed in a 500 mL Florentine and cooled in an ice-bath. Pre-mixed TFA:DCM:water (1:1:0.025, 4.5 mL) was added in one portion and the resultant solution was stirred at 0° C. for 0.75 hours and a further 0.75 hours at room temperature. The reaction mixture was concentrated under reduced pressure and azeotroped with portions of DCM (5×50 mL) and Et2O (5×50 mL). The solid obtained was triturated with Et2O, filtered and washed with Et2O (3×5 mL) to give a light yellow powder (3.51 g, 99% yield). δH (d6 DMSO) 3.6-3.7(3H, s), 8.3(1H, d), 8.6(1H, d), 8.8(1H, s), 9.9-10.0(1H, s), 13.8-14.0(1H, br s)

Provenance & Evidence