Dimethyl Sulfoxide → 2-(Pyrrolidin-1-yl)cyclohexanone

Participants

Reaction Steps

A solution of oxalyl chloride (50 mL, 0.5732 mol) in 200 mL of freshly distilled CH2Cl2 was cooled down to -70° C. and DMSO (80 mL, 1.1274 mol) was carefully added dropwise. After 15 min., 2-(1-pyrrolidinyl)cyclohexanol (a) (70 g, 0.4142 mol) was added to the reaction mixture, followed by Et3N (350 mL). The cold bath was then removed, and the mixture was stirred at room temperature for two and a half hours. Progress of the reaction was followed by gas chromatography. The solvent was partially removed in vacuo and ethyl ether (200 mL) was added. This organic layer was washed with brine (3×100 mL), dried (Na2SO4), and the solvent removed in vacuo. The crude product was distilled under high vacuum (BP: 84° C./0.5 mmHg) to yield 49.5 g of the ketone (b) as a colorless oil (72%). Rf : 0.49 (CHCl3 :MeOH:NH4OH=92:7:1); B.P: 84° C. (0.5 mmHg); IR (neat) 2940, 2860, 2800, 1715, 1440 cm-1 ; 1H-NMR (CDCl3) d 1.53-1.63 (m, 1H), 1.72 (m, 4H), 1.76-1.93 (m, 4H), 1.94-2.04 (m, 1H), 2.21, (m, 1H), 2.52 (m, 5H), 2.83 (dd, 1H, J1 =8.6, J2 =4.5 Hz); Mass Spectrum Calcd. for C10H17NO: 167.1310, Found: 167.1310.

Provenance & Evidence