Acetic Acid → HCID 71599540, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of tert-butyl 2-((2-(dimethylamino)-2-oxoethyl)(4-methoxyphenyl)amino)acetate (16) (1.98 g, 6.14 mmol) and di-tert-butyl oxalate (1.37 g, 6.76 mmol) in anhydrous tert-butanol (6 mL) was added potassium tert-butoxide (20 wt. % in THF) (10.77 ml, 15.35 mmol) and the reaction was stirred at 100° C. for 1.5 h, di-tert-butyl oxalate (300 mg, 1.5 mmol), potassium tert-butoxide (20 wt. % in THF) (4 mL, 5.71 mmol), THF (10 mL), and tert-butanol (4 mL) were added and the mixture stirred for a further 1 h. The mixture was allowed to cool to RT and acetic acid (4 ml, 69.9 mmol) added, the mixture was poured on to ice-cold water (50 mL) and the resulting precipitate was collected by vacuum filtration and recrystallised from hot ethanol to afford tert-butyl 5-(dimethylcarbamoyl)-3,4-dihydroxy-1-(4-methoxyphenyl)-1H-pyrrole-2-carboxylate (UL1-036) (890 mg, 37%) as a white powder: m/z 377 (M+H)+ (ES+); 375 (M−H)− (ES−). 1H NMR (400 MHz, DMSO-d6) δ: 8.62 (s, 1H), 8.45 (s, 1H), 7.12-6.99 (m, 2H), 6.94-6.81 (m, 2H), 3.76 (s, 3H), 2.83 (br s, 6H), 1.17 (s, 9H).

Provenance & Evidence