Dimethyl Sulfoxide → (R)-2-(Trityl-amino)-butyraldehyde

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of DMSO (3.0 mL, 2.8 eq, 42.28 mmol) in DCM (30 mL) under an argon atmosphere at −45° C., was added oxalyl chloride (2 M in DCM, 10.56 mL, 1.40 eq, 21.12 mmol), dropwise. The reaction mixture was stirred at −45° C. for 1 h, after which time a solution of (R)-2-(trityl-amino)-butan-1-ol (5 g, 1 eq, 15.08 mmol) in DCM (30 mL) was added dropwise with stirring. The reaction mixture was stirred at this temperature for 3 h, when TLC (hexane:ether; 80:20) indicated that the reaction had gone to completion. To the reaction mixture was added a solution of TEA (10.5 mL, 5 eq, 75.33 mmol) in DCM (30 mL), and the solution allowed to warm to room temperature over 16 h. The reaction mixture was diluted with more DCM (200 mL) and washed with water (250 mL). The aqueous phase was extracted with DCM (3×50 mL), and the combined organic phase washed with brine (50 mL), dried (MgSO4) and evaporated in vacuo. The residue was dissolved in ether (30 mL), the solid precipitate removed by filtration and the filtrate was evaporated in vacuo. The residue was dissolved in hexane (50 mL), the solid precipitate removed by filtration and the filtrate was evaporated in vacuo to afford the title compound as a light yellow oil. Yield: 2.59 g (52%). 1H-NMR (d6-DMSO, 250 MHz): δ 0.77 (t, 3H, J=7.42 Hz, —NHCH(CH2CH3)CHO), 1.34-1.61 (m, 2H, —NHCH(CH2CH3)CHO), 2.92 (m, 1H, —NHCH(CH2CH3)CHO), 3.62 (d, 1H, J=8.21 Hz, —NHCH(CH2CH3)CHO), 7.16-7.46 (m, 15H, 3×Ph), 8.77 (d, 1H, J=3.00 Hz, —NHCH(CH2CH3)CHO).

Provenance & Evidence