反应详情

Part D. To a solution of N'-(2,4-difluorophenyl)-N-heptyl-N-5-hydroxypentylurea (15.0 g, 0.042 mol) and carbon tetrabromide (16.75 g, 0.051 mol) in methylene chloride (350 mL) under a nitrogen atmosphere at ambient temperature, a solution of triphenylphosphine (13.24 g, 0.051 mol) in methylene chloride (100 mL) was added slowly. The reaction mixture was stirred for 3 hours and was concentrated in vacuo to give crude viscous oil. The product was purified by flash chromatography on silica gel (400 mL) eluting with hexane:ethyl acetate (90:10 v:v) to give N-(5-bromopentyl)-N'-(2,4-difluorophenyl)-N-heptylurea as a viscous colorless oil (17.5 g, 0.042 mol). 1H NMR (CDCl3) δ 8.14-8.00(m, 1H), 6.92-6.79(m, 2H), 6.35(bs, 1H), 3.49-3.25(m, 6H), 1.99-1.26 (m, 16H), 0. 915 (t, 3H).

1. concentrationwas concentrated in vacuo
2. customto give crude viscous oil
3. customThe product was purified by flash chromatography on silica gel (400 mL)
4. washeluting with hexane:ethyl acetate (90:10 v:v)