p-Toluenesulfonic acid → HCID 22677350, compound

Participants

Reaction Steps

A solution of N-(2-hydroxyphenyl)-4-amino-5,6-dichloropyridine-2-carboxamide (1.80 g, 5.7 mmol) (obtained from N-(2-hydroxyphenyl)-2-(4,5,6-trichloro)pyridinecarboxamide via azide formation followed by sodium borohydride reduction) and p-toluenesulfonic acid (0.2 g) in toluene (50 mL) was refluxed overnight under nitrogen with a Dean-Stark trap. After cooling, the reaction mixture was diluted with ethyl acetate and THF, and the organic mixture washed with saturated aqueous sodium bicarbonate. The organic layer was dried, concentrated, and the residue triturated with petroleum ether/diethyl ether to provide 4-amino-2,3-dichloro-6-(2-benzoxazolyl)pyridine (1.30 g, 4.6 mmol). 1H NMR (DMSO-d6): δ 7.82 (d, 2H), 7.66 (s, 1H), 7.55-7.38 (m, 2H), 7.18 (br.s, 2H).

Provenance & Evidence