Glycine ethyl ester → {[8-((R)-1-phenyl-propylcarbamoyl)-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-6-carbonyl]-amino}-acetic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of 8-((R)-1-phenyl-propylcarbamoyl)-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-6-carboxylic acid (Comp. No. 11a) (50 mg, 0.168 mmol) in dimethylformamide (1.7 ml) was added 1-hydroxybenzotriazole (23 mg, 0.168 mmol) and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (32 mg, 0.168 mmol). The mixture was stirred for 1 h at 40° C., then amino-acetic acid ethyl ester (17 mg, 0.168 mmol) was added and the mixture was stirred at 25° C. overnight. Excess dichloromethane was added and the mixture was washed consecutively with water, aqueous sodium hydrogencarbonate and brine. The organic layer was evaporated to dryness. The residue was dissolved in a small amount of acetonitrile, excess water was added and the solution was freeze-dried to give 52 mg (82%) of {[8-((R)-1-phenyl-propylcarbamoyl)-3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-6-carbonyl]-amino}-acetic acid ethyl ester. LC/MS (method 4): Rt=1.19 min; m/z=414.2 (M+H+). 1H-NMR: δ (ppm)=8.46 (1H, t), 8.21 (1H, d), 7.35-7.36 (3H, m), 7.30 (2H, t), 7.21 (1H, t), 4.91 (2H, dd), 4.82 (1H, q), 4.19 (2H, t), 4.11 (2H, q), 3.90-3.92 (4H, m), 1.71-1.83 (2H, m), 1.21 (3H, t), 0.88 (3H, t).

Provenance & Evidence