Hydrochloric Acid → 1-butyl-4-hydroxy-1,8-naphthyridin-2(1H)-one

Participants

Reaction Conditions

Reaction Steps

A slurry of the product of Example 89A (3.24 g, 11.16 mmol) in 2 N sodium hydroxide (100 mL) was heated at reflux for 3 hours, cooled to 11° C. and treated dropwise with concentrated hydrochloric acid to a constant pH of 3. The resulting white solid was collected by filtration, washed with water and dried to give the title compound (2.47 g, quantitative). MS (APCI+) m/z 219 (M+H)+. 1H NMR (300 MHz, DMSO-d6) δ ppm 0.90 (t, J=7.35 Hz, 3 H) 1.32 (m, 2 H) 1.57 (m, 2 H) 4.31 (m, 2 H) 5.89 (s, 1 H) 7.27 (dd, J=7.72, 4.78 Hz, 1 H) 8.23 (dd, J=7.72, 1.84 Hz, 1 H) 8.64 (dd, J=4.78, 1.84 Hz, 1 H) 11.61 (s, 1 H).

Provenance & Evidence