methyl N-(2,6-dimethylphenyl)carbamate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:80.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of toluene (150 mL), biphenyl (0.2 g) and sodium methoxide in methanol (23.76 g, 0.11 mol, 25% by weight) was heated at reflux, and the methanol-toluene azeotrope was removed. The mixture was allowed to cool to 80° C., and toluene (80 mL) was added. To the resulting mixture was added in five portions methyl (2,6-dimethylphenyl)carbamate (17.9 g, 0.1 mol). The methanol formed in the reaction was removed as the above azeotrope. When most of the methanol had been removed, ethylene glycol dimethyl ether (8 mL) was added, and the mixture was distilled until the head temperature reached 110° C. The mixture was allowed to cool to 25° C., and ethylene glycol dimethyl ether (3 mL) was added. The mixture was then added to phosgene in toluene (22.5 g, 0.56 mol, 25% by weight). When the addition was complete, excess phosgene was removed by distillation. The mixture was allowed to cool to 25° C., and then washed with sodium bicarbonate solution (40 mL, saturated). The organic layer was dried and the volatiles removed by evaporation to give 17.21 g (64.5%) of the title compound as a solid. An analytical sample was prepared by column chromatography on silica gel using 1:3 ethyl acetate-hexanes as the eluent. was heated at reflux the methanol-toluene azeotrope was removed toluene (80 mL) was added was removed as the above azeotrope When most of the methanol had been removed ethylene glycol dimethyl ether (8 mL) was added the mixture was distilled until the head temperature reached 110° C to cool to 25° C. ethylene glycol dimethyl ether (3 mL) was added When the addition excess phosgene was removed by distillation to cool to 25° C. washed with sodium bicarbonate solution (40 mL, saturated) The organic layer was dried the volatiles removed by evaporation