2,5-Pyridinediamine → Methyl 3-((6-aminopyridin-3-yl)carbamoyl)-4-methylbenzoate

Participants

Reaction Steps

In a round-bottomed flask was charged 5-(methoxycarbonyl)-2-methylbenzoic acid (0.2 g, 1.0 mmol), dicloromethane (3 ml), n,n-diisopropylethylamine (0.7 ml, 4.0 mmol), HOBt (0.16 g, 1.2 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.24 g, 1.2 mmol), and 2,5-diaminopyridine (0.11 g, 1.0 mmol) in that order. The reaction mixture was stirred at RT under N2 for 18 h. The reaction was partitioned between DCM (30 ml) and brine (20 mL). The aqueous layer was back extracted with DCM (3×15 mL) and the combined DCM layer was dried (Na2SO4) and concentrated. The crude product was dissolved in MeOH and absorbed on silica gel, pyrified by chromatography through a Redi-Sep 40 g column, eluting with a gradient of 0% to 10% MeOH in CH2Cl2, to provide methyl 3-((6-aminopyridin-3-yl)carbamoyl)-4-methylbenzoate as a tan solid. MS (ESI, pos. ion) m/z: 286.2 (M+1).

Provenance & Evidence