Dimethyl Sulfoxide → (S)-2-Dibenzylamino-propionaldehyde

Participants

Reaction Steps

Dry DMSO (0.53 mL, 7.43 mmol) was added to a stirred solution of oxalyl chloride (0.31 mL, 3.6 mmol) in CH2Cl2 (7.5 mL) at -78° C. The solution was allowed to stir 15 minutes followed by the addition of 40 (740 mg, 2.90 mmol) in CH2Cl2 (7.5 mL). After 30 minutes, Et3N (1.0 mL, 7.2 mmol) was added and allowed to warm to rt. The solution was extracted with satd. NaHCO3 (20 mL) and the aqueous layer was extracted with CH2Cl2 (2×15 mL). The organic layer was washed with satd. NaCl solution, dried with MgSO4 an concentrated in vacuo at rt to give 720 mg (98% yield) of a yellow oil which became a solid when cooled to -20° C. The aldehyde was used without further purification: mp 52-54° C. Lit. mp 55.5° C.; [α]26D =-36.0 (c 1,CHCl3Lit. [α]20D =-35.1 (c 1, EtOAc); 1H NMR (400 MHz, CDCl3) δ 1.19 (d, 2H, J=7.0 Hz), 3.34 (q, 1H, J=7.0 Hz), 3.58 (d, 2H, J=13.7 Hz), 3.74 (d, 2H, J=13.7 Hz), 7.26 (m, 2H), 7.33 (m, H), 7.42 (m,4H), 9.74 (s, 1H); 13C NMR (100 MHz) δ 6.7, 54.9, 62.8, 3.3, 4.4, 4.8, 139.1, 204.6; FABMS m/z 408.2 (M+MB), 254.2 (M+H), 22.2 (M--CHO); HRFABMS calcd for C17H20NO Mr 254.1545 (M+H), found Mr 254.1545. See, Dix et al., Arch Pharm (Weinheim) 1995, 328, 203-205.

Provenance & Evidence