Sodium Azide → Ethyl (1-benzyl-2-methyl-1H-pyrrolo[2,3-b]pyridin-4-yloxy)acetate

Participants

Reaction Conditions

Reaction Steps

1-Benzyl-2-methyl-1,5-dihydro-pyrrolo[3,2-c]pyridin-4-one, 9: 3-(1-Benzyl-5-methyl-1H-pyrrol-2-yl)-acrylic acid, 6 (26.72 g, 110.9 mmol) was dissolved in a dry acetone (1050 mL). To the suspension mixture triethylamine (35 mL) was added to form a clear solution. The reaction mixture was cooled to 0° C. and then to the cooled reaction mixture a solution of ethyl chlorofomate (30 mL, 304 mmol) in dry acetone (650 mL) was added dropwise over 1 hour. After addition the reaction mixture was stirred for 4 h at 0° C. Then to the reaction mixture was added dropwise the solution of sodium azide (14.52 g, 223 mmol) in H2O (175 mL) over 30 minutes. The reaction mixture was stirred at 0° C. for 2 h. The reaction mixture was poured into ice-water (1 L). Then the mixture was extracted with dichloromethane (3×1 L). The organic layers were combined and dried over MgSO4. The mixture was filtered and concentrated to afford a crude 8 as a yellow solid (32 g). To the mixture of diphenyl ether (175 mL) and tributylamine (31 mL) which was preheated to 205° C. was added dropwise the solution of crude 8 in diphenyl ether (250 mL) at 205° C. for 1 hour. After addition the mixture was stirred for another hour at 205° C. The mixture was cooled to room temperature and solid was formed. Diethyl ether (500 mL) was added into the reaction mixture to form more solid. The mixture was filtered and the solid was washed with diethyl ether to afford the product (8.81 g). The filtrate was concentrated and the residue was purified by silica gel chromatography (hexane to hexane:ethyl acetate, gradient 1:1 to 1:3; then methanol in dichloromethane, 1% to 5%) to afford 1-benzyl-2-methyl-1,5-dihydro-pyrrolo[3,2-c]pyridin-4-one, 9 as a yellow solid (4.7 g). Yield: 13.51 g, (51%)

Provenance & Evidence