Trifluoromethanesulfonic anhydride → HCID 59465791, compound

Participants

Reaction Conditions

Reaction Steps

Prepared using general procedure 57. Under an N2 atmosphere at −20° C., diisopropyl ethyl amine (7.59 g, 10.23 mL, 58.77 mmol) was added drop wise to a solution of solution of (R)-3-hydroxydihydrofuran-2(3H)-one (3 g, 29.38 mmol) in dichloromethane (50 mL). Then added trifluoromethanesulfonic anhydride (8.69 g, 5.18 mL, 30.81 mmol) drop wise by maintaining internal temperature of the reaction mixture <−20° C. Upon completion of addition, the mixture was stirred at −20° C. for 1 hour. Then added at −20° C., 4-chloro-indoline (6.74 gm, 44.07 mmol) drop wise. The reaction was allowed to warm to RT over a period of 30 minutes and continued to stir at RT for 16 hrs. The reaction mixture was diluted with 200 mL of ethylacetate and washed with saturated sodium bicarbonate (3×50 mL). The organic layer was washed with a saturated aqueous NaCl solution (2×50 mL). The solution was dried over magnesium sulfate, filtered, and concentrated. Purification via silica gel chromatography using 10-30% ethyl acetate in hexane gave (S)-3-(4-chloroindolin-1-yl)dihydrofuran-2(3H)-one as a white solid (5.47 g, 80% yield). 1H NMR (400 MHz, DMSO-d6) δ 7.03 (t, J=8.0 Hz, 1H), 6.63 (dd, J=0.6, 8.0 Hz, 1H), 6.51 (d, J=7.9 Hz, 1H), 4.91 (dd, J=9.2, 11.2 Hz, 1H), 4.45-4.40 (m, 1H), 4.30-4.23 (m, 1H), 3.55-3.48 (m, 1H), 3.28 (dd, J=8.5, 18.0 Hz, 1H), 2.99-2.94 (m, 2H), 2.40-2.32 (m, 2H). LC/MS (10%-99% CH3CN (0.035% TFA)/H2O (0.05% TFA)), m/z: M+1 obs=237.9; tR=1.51 min.

Provenance & Evidence