Trifluoromethanesulfonic anhydride → N-((4aS,5S,7aS)-7a-(2,3-difluorophenyl)-5-(trifluoromethyl)-4a,5,7,7a-tetrahydro-4H-furo[3,4-d][1,3]thiazin-2-yl)benzamide

Participants

Reaction Conditions

Reaction Steps

N-(((3 S,4R,5 S)-3-(2,3-Difluorophenyl)-4-(hydroxymethyl)-5-(trifluoromethyl)tetrahydrofuran-3-yl)carbamothioyl)benzamide (2.99 g) was dissolved in pyridine (14 mL), and the mixture cooled to −20° C. Trifluoromethanesulfonic anhydride (1.55 mL) was added dropwise over 10 min and the reaction mixture was allowed to warm to −10° C. After stirring for 2 h, a further portion of trifluoromethanesulfonic anhydride (1.0 mL) was added dropwise over 10 min, the reaction was stirred for a further 2 h, and was then quenched by the addition of ammonium chloride (sat., aq., 50 mL) and extracted with EtOAc (3×100 mL). The combined organic extracts were dried over MgSO4, concentrated in vacuo and purified by silica gel column chromatography (5% to 20% EtOAc/hex) to obtain the title compound (1.20 g). 1H NMR (400 MHz, CDCl3) δ ppm 2.86 (d, J=10.6 Hz, 1 H), 3.20 (br. s., 1 H), 3.55 (br. s., 1 H), 4.04 (br. s., 1 H), 4.65 (d, J=8.8 Hz, 1 H), 4.81 (br. s., 1 H), 7.06-7.24 (m, 3 H), 7.40-7.64 (m, 3 H), 7.82-8.21 (m, 2 H)

Provenance & Evidence