反应详情

A solution of 25 g (0.05 mol) of 3-(octadecyloxy)-5-(phenylmethoxy)benzoic acid, 13 ml (0.06 mol) of diphenylphosphoryl azide and 8.4 ml (0.06 mol) of triethylamine in 165 ml of t-butyl alcohol (freshly distilled from sodium) was stirred at reflux under argon for 19 hours. The excess t-butylalcohol was removed at reduced pressure and the residue was extracted with methylene chloride. The dried extract was concentrated to a solid which was purified by chromatography on 200 g of 35-70 mesh silica gel using 50%ethyl acetate-hexane to give 28 g of slightly impure 3-(octadecyloxy)-5-(phenylmethoxy)phenylcarbamic acid dimethylethyl ester which was suitable for use in the next step.

1. temperatureat reflux under argon for 19 hours
2. customThe excess t-butylalcohol was removed at reduced pressure
3. extractionthe residue was extracted with methylene chloride
4. extractionThe dried extract
5. concentrationwas concentrated to a solid which
6. customwas purified by chromatography on 200 g of 35-70 mesh silica gel using 50%ethyl acetate-hexane