Carbon tetrabromide → N-(5-bromopentyl)-N'-(2,4-difluorophenyl)-N-heptylurea

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Reaction Steps

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) δ8.14-8.00(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).

Provenance & Evidence