Water → 3-(5-Fluorobenzothiazol-2-yl-trans-ethenyl)benzaldehyde

Participants

Reaction Conditions

Reaction Steps

To a solution of 1.5 g of 3-(5-fluorobenzothiazol-2-yl-trans-ethenyl)benzyl alcohol (Preparation H2) in 40 ml of methylene chloride and 25 ml of dimethylsulfoxide at -60° C. was added a solution of 0.64 ml of oxalyl chloride in 20 ml of dry methylene chloride containing 0.74 ml of dimethylsulfoxide. After stirring at -60° C. for 35 minutes the reaction mixture was allowed to warm to -35° C. for 25 minutes. The mixture was again cooled to -60° C. and 3.65 ml of triethylamine was added over a period of 5 minutes. The mixture was allowed to warm to room temperature and was treated with 200 ml of water. The organic phase was washed with a brine solution, dried over sodium sulfate and concentrated in vacuo to give after trituration with ethyl acetate--hexane 1.2 g. A sample was recrystallized from ethyl acetate--hexane, m.p. 151°-152° C.

Provenance & Evidence