Diisopropylethylamine → Methyl 4-[(6-chloro-3-methyl-pyridine-2-carbonyl)amino]-3,5-dimethyl-benzoate

Participants

Reaction Steps

To a suspension of potassium 6-chloropyridine-2-carboxylate (52 g, 265.8 mmoles) in dimethylformamide (676 mL) is added bis(2-oxo-3-oxazolidinyl)phosphonic chloride (115 g, 451.8 mmoles). The mixture is stirred at ambient temperature for 30 minutes. Methyl 4-amino-3,5-dimethyl-benzoate (42.9 g, 239.2 mmoles, see preparation 12) and diisopropylethylamine (115.9 mL, 664.5 mmoles) are added. The reaction is stirred at ambient temperature for 16 hours. The mixture is then poured into water (2000 mL) and is stirred for 30 minutes. The resulting solid is filtered and dried under reduced pressure at 45° C. The dry material is triturated with hexane (1400 mL) over 2 hours. The solid is filtered and dried under vacuum to give the title compound (69 g, 78%) as a white solid. Mass spectrum (m/z): 333.05 (M+1). 1H NMR (300 MHz, DMSO): 10.16 (s, 1H), 7.89 (d, J=8.2 Hz, 1H), 7.73 (s, 2H), 7.63 (d, J=8.2 Hz, 1H), 3.85 (s, 3H), 2.49 (s, 3H), 2.28 (s, 6H).

Provenance & Evidence