Water → Ethyl 1-(2-bromobenzyl)-4-oxo-1,4-dihydro-1,5-naphthyridine-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a brown solution of (Z)-ethyl 2-(3-chloropicolinoyl)-3-(dimethylamino)acrylate (35) (850 mg, 3.01 mmol) in DMA (dimethylacetamide) (50 mL) were added a solid powder of tribasic potassium phosphate (1.4 g, 6.61 mmol) and then (2-bromophenyl)methanamine (615 mg, 3.31 mmol) at room temperature under a nitrogen atmosphere. The resulting brown suspension was heated to 74° C. and stirred for 15 h at which time LCMS analysis indicated the absence of starting material. Then, it was cooled to room temperature and poured slowly into water (100 mL). Then, the organic compound was extracted into dichloromethane (2×200 mL). The combined extracts were washed with water, brine solution, and dried over anhydrous MgSO4. Filtration and concentration gave a crude brown oil which was purified using an ISCO (120 g) column, eluting with ethyl acetate in hexanes (0 to 100%) and then 5 to 10% methanol in dichloromethane. The pure fractions were combined and the solvent was removed under vacuum to obtain ethyl 1-(2-bromobenzyl)-4-oxo-1,4-dihydro-1,5-naphthyridine-3-carboxylate (36) (574 mg, 46.8% yield) as a light brown solid.

Provenance & Evidence