Diisopropylethylamine → Methyl 4-[(2-chloroquinoline-4-carbonyl)amino]-3,5-dimethyl-benzoate

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-chloroquinoline-4-carboxylic acid (5.00 g, 0.0024 mol) in CH2Cl2 (50 mL) at 0° C. are added methyl 4-amino-3,5-dimethylbenzoate (3.88 g, 0.02167 mol, see preparation 12) and N,N-diisopropylethylamine (12.5 ml, 0.07225 mol). After stirring the reaction mixture for 10 minutes, 1-propanephosphonic acid cyclic anhydride (50% solution in ethyl acetate, 31.0 ml, 0.048 mol) is added via syringe and heated at 40° C. After 5 hours, the reaction mixture is diluted with water and extracted with dichloromethane. The organic layers are combined and dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The resulting residue is purified by flash chromatography (silica gel) using a gradient of 0-40% ethyl acetate in hexanes. After purification the solid is triturated with 20% diethyl ether in pentane and dried to give the title compound as a white solid (8.50 g, 96%). Mass spectrum (m/z): 369.1 (M+1).

Provenance & Evidence