N,N-Dimethylthioformamide → 2-(5-fluoro-2-methoxyphenyl)-2-hydroxy-N,N-dimethylethanethioamide

Participants

Reaction Conditions

Reaction Steps

To a solution of lithium diisopropylamide, 2M in THF/n-heptane (210 mL, 583 mmol) was added THF (100 mL) and the solution cooled to −78° C. under nitrogen. This was then added dropwise over 1 h to a solution of the 5-fluoro-2-methoxybenzaldehyde (50 g, 0.32 mmol) and N,N-dimethylthioformamide (34.7 g, 389 mmol) in dry THF (200 mL). This was warmed to −5° C. and quenched with water (400 mL). The solution was filtered and washed with diethyl ether, the aqueous layer was extracted with ether (1 L). The combined organic layers were washed with water (500 mL), dried (MgSO4) and the solvent removed in vacuo to give a crystalline suspension in oil. This was triturated in ether and filtered to give a crystalline solid (21.8 g, 28%); δH (300 MHz, CDCl3) 7.16-6.81 (3H, m, ArH), 5.81-5.75 (1H, m, CHOH), 5.31-5.22 (1H, m, OH), 4.89 (3H, s, OCH3), 3.50 (3H, s, N(CH3)2) and 3.08 (3H, s, N(CH3)2).

Provenance & Evidence