Dichloromethane → HCID 66833616, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of (R)-tert-butyl 3-pent-4-enoylpyrrolidine-1-carboxylate (300 mg, 1 mmol) in methylene chloride (5 mL, 80 mmol) was added trifluoroacetic acid (2 mL, 20 mmol) and the resultant mixture was stirred at room temperature for 1 h. The crude reaction mixture was then concentrated to obtain a crude oil which was re-dissolved in methylene chloride (5 mL, 80 mmol) prior to the addition of triethylamine (1 mL, 7 mmol). This solution was cooled to 0° C. before adding 2-nitrobenzenesulfonyl chloride (450 mg, 2.0 mmol) in a single portion. The reaction mixture, which immediately turned blue in color, was stirred overnight at room temperature. At the end of the reaction, the solution was diluted with saturated aqueous sodium bicarbonate (50 mL) to give two layers which were separated. The aqueous layer was further extracted with methylene chloride (2×20 mL) and the combined organic layers were dried over Na2SO4, filtered and concentrated to give a blue oil, which was purified by flash column chromatography (silica gel, eluting with 0-100% ethyl acetate in hexanes) to give (R)-1-(1-(2-nitrophenylsulfonyl)pyrrolidin-3-yl)pent-4-en-1-one (305 mg, 80%). 1H NMR (400 MHz, CDCl3) δ 8.07-8.03 (m, 1H), 7.76-7.70 (m, 2H), 7.66-7.62 (m, 1H), 5.78 (ddt, J1=17.0 Hz, J2=10.4 Hz, J3=6.5 Hz, 1H), 5.07-4.97 (m, 2H), 3.70 (dd, J1=12.0 Hz, J2=8.0 Hz, 1H) 3.61 (dd, J1=12.0 Hz, J2=8.1 Hz, 1H), 3.52 (t, J=8.1 Hz, 2H), 3.24 (p, J=8.0 Hz, 1H), 2.59 (td, J1=7.3 Hz, J2=3.6 Hz, 2H), 2.32 (q, J=6.8 Hz, 2H), 2.24-2.16 (m, 1H), 2.14-2.05 (m, 1H), 1.28 (ddd, J1=17.8 Hz, J2=10.6 Hz, J3=7.3 Hz, 1H); ESI MS found for C15H18N2O5S m/z 339.3 (M+H)+.

Provenance & Evidence