Acetic Acid → HCID 18697818, compound

Participants

Reaction Steps

To a solution of diisopropylamine (1.1 ml, 7.70 mmol) in tetrahydrofuran (12 ml) was added, at -78° C. under an argon atmosphere, 1.5 N butyllithium (4.8 ml, 7.22 mmol). The mixture was stirred for 30 min. Ethyl propiolate (0.9 ml, 8.66 mmol) and a solution of 4-acetylamino-2-nitrobenzaldehyde (1.0 g, 4.81 mmol) in tetrahydrofuran (6 ml) were added in that order, and the mixture was further stirred at -78° C. for one hr. A solution of acetic acid (0.9 ml, 14.91 mmol) in tetrahydrofuran (3 ml) was then added thereto, followed by extraction with ethyl acetate. The organic layer was washed with dilute hydrochloric acid, water, a saturated aqueous sodium bicarbonate solution, and saturated brine in that order. It was then dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure to give ethyl 4-hydroxy-4-(4-acetylamino-2-nitrophenyl)-2-butynoate (1.613 g) as an oil. Ethyl 4-hydroxy-4-(4-acetylamino-2-nitrophenyl)-2-butynoate thus prepared was dissolved in toluene (14 ml), 4-methoxybenzylazide (2.35 g, 14.4 mmol) was added to the solution, and the mixture was stirred at 10° C. for 18 hr. The reaction mixture was cooled to room temperature, and the resultant crystal as a precipitate was collected by suction filtration to give a 3:1 mixture (1.09 g, 48%) of ethyl 4-hydroxy-(4-acetylamino-2-nitrophenyl)methyl-1-(4-methoxybenzyl)-1,2,3-triazole-5-carboxylate (a-1) and ethyl 5-hydroxy-(4-acetylamino-2-nitrophenyl)methyl-1-(4-methoxybenzyl)-1,2,3-triazole-4-carboxylate (a-2).

Provenance & Evidence