反应详情

温度

60 °C

Phosphortribromide (6.83 g, 25.22 mmol) was added dropwise to a stirred solution of 2,3,4-trimethoxybenzyl alcohol (10 g, 54.44 mmol) in dichloromethane (100 ml), cooled at 0° C. After 30 min of vigorous stirring, the reaction mixture was slowly quenched with 100 g of ice-water. The dichloromethane layer was separated and the aqueous layer was further extracted with dichloromethane (2×100 ml). The combined extracts were twice washed with a saturated solution of sodium chloride (2×150 ml). The organic solution was dried over magnesium sulphate and evaporated to give 10 g (yield 76%) of the benzylbromide 2 as a colourless oil. As soon as isolated, the benzyl bromide compound was directly used for the next step. In fact the compound degradated after one night even at +4° C. The obtained 1-bromomethyl-2,3,4-trimethoxybenzene oil was treated with KCN (6.52 g, 100 mmol) in dry DMF (30 ml), at 0° C. and under nitrogen atmosphere. The obtained mixture was stirred for 3 g at 0° C. and 1 h at 60° C. The cooled reaction mixture was poured into water (80 ml) and extracted with diethylether (3×150 ml). The crude benzylcyanid was chromatographed on silica (diethylether/petroleumether: 1/3) to give 2,3,4-trimethoxyphenyl-acetonitrile as a white crystalline material (Yield: 6.8 g; 86%).

1. customAs soon as isolated
2. waitIn fact the compound degradated after one night even at +4° C
3. customThe cooled reaction mixture
4. extractionextracted with diethylether (3×150 ml)
5. customThe crude benzylcyanid was chromatographed on silica (diethylether/petroleumether: 1/3)