Hydrochloric Acid → 1,6-Naphthyridine

Participants

Reaction Conditions

Reaction Steps

A sulfuric acid solution was prepared by adding H2SO4 (100 mL) to H2O (57 mL) cooled in an ice bath. To this solution was added glycerol (33 mL, 457 mmol), m-nitrobenzene sulfonic acid sodium salt (48 g, 212 mmol) and 4-amino-pyridine (10 g, 106 mmol). The reaction mixture was heated at 135° C. for 4 hours. The cooled reaction mixture was basicified with 2.5 N NaOH (500 mL) with cooling in an ice bath, and extracted into CH2Cl2 (3×200 mL). The organic fractions were combined, dried over Na2SO4 and concentrated. The resulting oil was purified by column chromatography (5% MeOH/CH2Cl2) affording 5.04 g (36%) as a dark orange oil. An analytical sample was prepared as the HCl salt from EtOAc yielding an orange low melting solid. MS EI m/z 130 M+.

Provenance & Evidence