Ethylamine → N-ethyl-3-chloro propylsulfonamide

To a solution of 3-chloropropylsulfonyl chloride 1 (6.1 g, 34.5mmol) in ether (25 ml) was dropwise added ethylamine (a 70% aqueous solution, 4.4 g, 68.3 mmol) with stirring and ice-cooling over 15 minutes, and the resultant mixture was stirred for one hour at room temperature. The reaction mixture was concentrated in vacuo, Benzene (100 ml) was added to the residue, and the solvent was removed in vacuo. To the residue was added ether (150 ml) and filtered to remove the insoluble material. The filtrate was distilled in vacuo to remove ether and 6.96 g (yield, about 100%) of crude N-ethyl-3-chloro propylsulfonamide (intermediate 3a) was obtained as colorless crystals (m.p.=30-32° C.). To a solution of this intermediate 3a (6.96 g, 34.5 mmol) in THF (50 ml) was slowly added sodium hydride (60% in oil, 1.52 g, 38.0 mmol) with stirring under ice-cooling over 15 minutes. The reaction mixture was stirred for another 30 minutes at room temperature. After the addition of ether (50 ml), the mixture was filtered to remove insoluble material and the solvent was distilled in vacuo to give 4.93 g (96%) of the desired compound 4a as a pale yellow oil. IR (CHCl3)cm−1: 3018, 2976, 2868, 1452, 1306, 1220, 1179, 1129, 1015; NMR (CDCl3) δ: 1.24 (3H, t, J=7.4 Hz, CH3), 2.28-2.42 (2H, m, CH2), 3.10 (2H, q, J=7.4 Hz, CH2), 3.15 (2H, t, J=7.6 Hz, CH2), 3.22-3.29 (2H, m, CH2).

1. temperatureice-cooling over 15 minutes
2. concentrationThe reaction mixture was concentrated in vacuo, Benzene (100 ml)
3. additionwas added to the residue
4. customthe solvent was removed in vacuo
5. additionTo the residue was added ether (150 ml)
6. filtrationfiltered
7. customto remove the insoluble material
8. distillationThe filtrate was distilled in vacuo
9. customto remove ether

ORD record

ord-617a06a078134a90be6a9932f0593bcb

Source dataset

uspto-grants-2003_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06525081B1