反应详情

Sodium acetate (VI, 9.702 g, 0.1182 mol) is added to a mixture of 1-formyl-4-(4-methoxyphenyl)piperazine (VI, 5.17 g, 23.5 mmol) and acetic acid (102 ml). When the sodium acetate had completely dissolved, a solution of bromine (7.912 g, 49.5 mmol) in acetic acid (9.5 ml) is added over 14 min. After 35 min the mixture is poured into water poured into water and extracted exhaustively with dichloromethane. The combined organic extracts are backwashed with water, followed by saturated sodium bicarbonate, dried over sodium sulfate and concentrated. The residue is chromatographed on silica gel eluting first with ethyl acetate/dichloromethane (10/90) and then ethyl acetate/dichloromethane (20/80). The appropriate fractions are pooled and concentrated to give 1-formyl-4-(2-bromo-4-methoxyphenyl)piperazine (VII), NMR (CDCl3) 2.94, 3.55, 3.74, 3.78, 6.83, 6.97, 7.16 and 8.10 δ.

1. extractionextracted exhaustively with dichloromethane
2. dry with materialdried over sodium sulfate
3. concentrationconcentrated
4. customThe residue is chromatographed on silica gel eluting first with ethyl acetate/dichloromethane (10/90)
5. concentrationconcentrated