Lithium hydroxide, monohydrate → HCID 90272154, compound

Participants

Reaction Steps

To a solution of ethyl 1-(biphenyl-2-ylmethyl)-7-methyl-4-oxo-1,4-dihydro-1,5-naphthyridine-3-carboxylate (20) (80 mg, 0.2 mmol) in methanol (10 mL) was added the solid lithium hydroxide monohydrate (168 mg, 4.02 mmol) at room temperature under nitrogen atmosphere. It gave a clear solution within 30 minutes and this light yellow solution was stirred for 15 h at which time LCMS analysis indicated the absence of starting material. Then, it was diluted with water and the methanol was removed under vacuum. The basic aqueous layer was diluted with water and then extracted with ethyl acetate (50 mL) to remove any neutral impurities. Then, the basic aqueous layer was neutralized with 1.0N HCl. Then, the acid was extracted with ethyl acetate (2×30 mL) and the combined extracts were washed with brine solution and dried over anhydrous MgSO4. Filtration and concentration gave the yellow solids which were dissolved in acetonitrile and water. The mixture was frozen and then lyophilized under high vacuum to obtain 1-(biphenyl-2-ylmethyl)-7-methyl-4-oxo-1,4-dihydro-1,5-naphthyridine-3-carboxylic acid (21) (15 mg, 20% yield) as a light yellow solid.

Provenance & Evidence