tert-butyl N-amino-N-cyclopropylcarbamate

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

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

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

Procedure: N-cyclopropyl-hydrazinecarboxylic acid tert-butyl ester. To a solution of 1.37 g of 3-(4-cyano-phenyl)-oxaziridine-2-carboxylic acid tert-butyl ester in Et2O (8 mL) was added 1.2 mL of cyclopropylamine. The mixture was aged for 2 h and then concentrated in vacuo. Chromatography on SiO2 (0 to 25% EtOAc/hexanes) provided an impure pale yellow solid that was sublimed under high vacuum in a 50° C. oil bath to afford 641 mg of the desired compound. 1H NMR (500 MHz, CDCl3): 6.31 (br s, 1H), 3.49 (br s, 1H), 2.74 (br s, 1H), 1.48 (s, 9H), 0.52-0.48 (m, 4H). concentrated in vacuo Chromatography on SiO2 (0 to 25% EtOAc/hexanes) provided an impure pale yellow solid that was sublimed under high vacuum in a 50° C.

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

Procedure: A mixture of N-cyclopropyl-hydrazinecarboxylic acid tert-butyl ester (Intermediate 28; 0.111 g, 0.64 mmol), phenylboronic acid (Aldrich; 156 mg, 1.3 mmol), copper(II) acetate (116 mg, 0.64 mmol) and triethylamine (180 μL, 1.3 mmol) in 1,2-dichloroethane (3 mL) was heated in an oil bath at 50° C. for 16 h. The mixture was allowed to cool, and it was then adsorbed onto silica gel and purified by chromatography using an ISCO 40 g column, eluting with 5-40% ethyl acetate/hexanes, to give N-cyclopropyl-N′-phenyl-hydrazinecarboxylic acid tert-butyl ester (72 mg, 45%) as a pale yellow solid. to cool purified by chromatography eluting with 5-40% ethyl acetate/hexanes

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

Procedure: Water (24 mL) was added over 1 min to a mixture of N-nitroso-N-cyclopropyl-carbamic acid tert-butyl ester (2.01 g, 10.8 mmol), zinc powder (7.2 g, 110 mmol) and ammonium chloride (8.8 g, 165 mmol) in methanol (48 mL). An exotherm and gas evolution were noted. The mixture was stirred at room temperature for 2.25 h and at 50° C. for 2 h. The mixture was allowed to cool. It was filtered through Celite, and the Celite was washed well with methanol. The colvents were evaporated and dichloromethane (250 mL) was added. Salts were filtered off and the solution was dried (magnesium sulfate), filtered, and evaporated. The residue was passed through a cotton plug with a small amount of dichloromethane, the solvent was evaporated to give a clear oil. This was purified by chromatography using an ISCO 120 g column, eluting with 10-60% ethyl acetate/hexanes to give N-cyclopropyl-hydrazinecarboxylic acid tert-butyl ester (207 mg, 11%) as a pale yellow oil, along with a 36% yield of over-reduced cyclopropyl-carbamic acid tert-butyl ester. to cool It was filtered through Celite the Celite was washed well with methanol The colvents were evaporated dichloromethane (250 mL) was added Salts were filtered off the solution was dried (magnesium sulfate) filtered evaporated the solvent was evaporated to give a clear oil This was purified by chromatography eluting with 10-60% ethyl acetate/hexanes

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

Procedure: N-cyclopropyl-hydrazinecarboxylic acid tert-butyl ester. To a solution of 1.37 g of 3-(4-cyano-phenyl)-oxaziridine-2-carboxylic acid tert-butyl ester in Et2O (8 mL) was added 1.2 mL of cyclopropylamine. The mixture was aged for 2 h and then concentrated in vacuo. Chromatography on SiO2 (0 to 25% EtOAc/hexanes) provided an impure pale yellow solid that was sublimed under high vacuum in a 50° C. oil bath to afford 641 mg of the desired compound. 1H NMR (500 MHz, CDCl3): 6.31 (br s, 1H), 3.49 (br s, 1H), 2.74 (br s, 1H), 1.48 (s, 9H), 0.52-0.48 (m, 4H). concentrated in vacuo Chromatography on SiO2 (0 to 25% EtOAc/hexanes) provided an impure pale yellow solid that was sublimed under high vacuum in a 50° C.