Potassium Carbonate → HCID 9802202, compound

Participants

Reaction Steps

This nitropyridine (775 mg, 3 mmol) was dissolved in a mixed solvent of acetic acid (30 ml) and conc. hydrochloric acid (1.5 ml), and zinc (4 g, 60 mmol) was added thereto in small portions while being cooled with ice. After the mixture was stirred for 10 minutes, the reaction mixture was filtered, and the filtrate was neutralized with a sodium hydroxide aqueous solution, and extracted with ethyl acetate. The organic layer was washed with water and then with a saturated aqueous solution of sodium chloride, and dried over sodium sulfate. Subsequently, the solvent was distilled off to obtain 590 mg (yield 86%) of 3-amino-2,6-bis(ethylthio)-6-methylpyridine as a yellow oil. Triethylamine (304 mg, 3 mmol) was added to a THF (10 ml) solution of this aminopyridine (590 mg, 2.6 mmol), and bromoacetyl bromide (606 mg, 3 mmol) was then slowly added thereto dropwise while being cooled with ice. The mixture was stirred at room temperature for 1 hour. The reaction mixture was filtered, and the filtrate was concentrated. Then, the residue was purified through silica gel chromatography (silica gel 60 g, eluent—hexane:acetone=10:1→5:1) to obtain 410 mg (yield 45%) of 2-bromo-N-[2,4-bis(ethylthio)-6-methyl-3-pyridyl]acetamide as a light brown needle crystal. Potassium carbonate (46 mg, 0.33 mmol) was added to an acetonitrile (3 ml) solution of this amide (105 mg, 0.3 mmol) and 2-mercaptobenzoxazole (45 mg, 0.3 mmol), and the mixture was stirred at room temperature for 2 hours. The reaction mixture was extracted with ethyl acetate. The organic layer was washed with water and then with a saturated aqueous solution of sodium chloride, and dried over magnesium sulfate. Subsequently, the solvent was distilled off, and the resulting crude product was purified through preparative thin-layer chromatography (eluent—hexane:ethyl acetate=3:1) to obtain 70 mg (yield 56%) of the desired compound as a colorless needle crystal.

Provenance & Evidence