benzyl N-(2-oxopropyl)carbamate

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

Procedure: A solution of 1 g of 2-benzyloxycarbonylaminomethyl-2-methyl-4-(1,2-dihydro-2-oxo-1-pyridyl)-6-cyano3-chromene [obtainable from 1-benzyloxycarbonylamino-2-propanone ("1-CBZ-2-propanone") via 2-CBZ-aminomethyl-2-methyl-6-cyano-4-chromanone, the corresponding 4-chromanol, the corresponding 3-chromene and the corresponding 3,4-epoxide] in 20 ml of dioxane is hydrogenated on 0.5 g of 5% Pd-carbon at 20° C. and 1 bar until the calculated amount of H2 has been absorbed. The mixture is filtered, the solution is evaporated and 2-aminomethyl-2-methyl-4-(1,2-dihydro-2-oxo-1-pyridyl)-6-cyano-3-chromene is obtained. 1 bar until the calculated amount of H2 has been absorbed The mixture is filtered the solution is evaporated

Conditions: temp:-78.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of oxalyl chloride (37 mL, 2 M solution in CH2Cl2, 74 mmol) in CH2Cl2 (60 mL) at −78° C. under argon was added DMSO (7.8 g, 100 mmol). The mixture was stirred at −78° C. for 20 min, and to this mixture was added a solution of 1-benzyloxycarbonylamino-2-propanol (2) (12.9 g, 61.8 mmol) in CH2Cl2 (40 mL). The mixture was stirred at −78° C. for 1 h, and then Et3N (21 mL) was added to the mixture. The mixture was warmed to room temperature and washed with 1 N hydrochloric acid followed by aqueous sodium bicarbonate solution. The organic solution was dried over Mg2SO4 and concentrated to afford 1-benzyloxycarbonylamino-2-propanone (10.2 g, 81%) as a solid, which was used without further purification in the next step. 1H NMR (CDCl3): □ 7.32 (m, 5H), 5.50 (s, 1H), 5.06 (s, 2H), 4.07 (s, 2H), 2.1 (s, 3H) The mixture was stirred at −78° C. for 1 h The mixture was warmed to room temperature washed with 1 N hydrochloric acid The organic solution was dried over Mg2SO4 concentrated

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

Procedure: A solution of 1 g of 2-benzyloxycarbonylaminomethyl-2-methyl-4-(1,2-dihydro-2-oxo-1-pyridyl)-6-cyano3-chromene [obtainable from 1-benzyloxycarbonylamino-2-propanone ("1-CBZ-2-propanone") via 2-CBZ-aminomethyl-2-methyl-6-cyano-4-chromanone, the corresponding 4-chromanol, the corresponding 3-chromene and the corresponding 3,4-epoxide] in 20 ml of dioxane is hydrogenated on 0.5 g of 5% Pd-carbon at 20° C. and 1 bar until the calculated amount of H2 has been absorbed. The mixture is filtered, the solution is evaporated and 2-aminomethyl-2-methyl-4-(1,2-dihydro-2-oxo-1-pyridyl)-6-cyano-3-chromene is obtained. 1 bar until the calculated amount of H2 has been absorbed The mixture is filtered the solution is evaporated