(4-Amino-phenyl)-methyl-carbamic acid tert-butyl ester

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of tert-butyl 4-aminophenyl(methyl)carbamate (36) (7 g, 31.5 mmol) and N,N-dibenzyl-6-chloro-5-nitropyrimidin-4-amine (1) (11.2 g, 31.5 mmol) in dioxane (100 mL) was added Et3N (8 mL) and the reaction mixture was stirred at 60° C. overnight. The mixture was cooled to room temperature, the solvent was evaporated before water (200 mL) and EA (100 mL) was introduced. The organic layer was separated and extracted with EA (60 mL×2). After the organic layer was washed with brine and dried over anhydrous sodium sulfate, the solvent was evaporated. The residue was purified by column chromatography (silica gel, 0 to 30% ethyl acetate in petroleum ether) to give tert-butyl 4-(6-(dibenzylamino)-5-nitropyrimidin-4-ylamino)phenyl(methyl)carbamate (37) 9 g as yellow solid (yield 53%). LC-MS (ESI): m/z (M+1) 541. The mixture was cooled to room temperature the solvent was evaporated before water (200 mL) and EA (100 mL) was introduced The organic layer was separated extracted with EA (60 mL×2) After the organic layer was washed with brine dried over anhydrous sodium sulfate the solvent was evaporated The residue was purified by column chromatography (silica gel, 0 to 30% ethyl acetate in petroleum ether)

Conditions: temp:50.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of N-methyl-4-nitroaniline (5.0 g, 32.9 mmol) in THF (50 mL) were added di-tert-butyl dicarbonate (10.76 g, 49.4 mmol) and DMAP (201 mg, 1.6 mmol). The reaction mixture was refluxed under N2 for 2 h before cooled to rt. After removal of the solvent, the residue was dissolved with EtOAc (200 mL). The resulting solution was washed with water and brine, dried over Na2SO4, and concentrated in vacuo to give tert-butyl methyl(4-nitrophenyl)carbamate (8.3 g, 100%) as a brown oil. To a solution of tert-butyl methyl(4-nitrophenyl)carbamate (8.3 g, 32.9 mmol) in THF/MeOH/H2O (150 mL/40 mL/80 mL) was added Fe powder (9.4 g, 168 mmol) and NH4C1 (18 g, 337 mmol). The reaction mixture was heated at 50° C. for 4 h under N2. After cooling to rt, the reaction mixture was filtered through a pad of Celite. The filtrate was extracted with EtOAc (100 mL×3), washed with water and brine, dried over Na2SO4, and concentrated in vacuo to afford tert-butyl 4-aminophenyl(methyl)carbamate (36) (7.3 g, yield 100%) as a yellow solid. LC-MS (ESI): m/z (M+1) 223. After cooling to rt the reaction mixture was filtered through a pad of Celite The filtrate was extracted with EtOAc (100 mL×3) washed with water and brine dried over Na2SO4 concentrated in vacuo