Sodium Bicarbonate → HCID 22592140, compound

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Reaction Steps

This nitropyridine (1.08 g, 3.77 mmol) was dissolved in a mixed solvent of acetic acid (35 ml) and conc. hydrochloric acid (1.6 ml), and zinc (2.96 g, 45.25 mmol) was added thereto in small portions while being cooled with ice. After the mixture was stirred for 1 hour, the reaction mixture was filtered, and the filtrate was neutralized with an aqueous solution of sodium hydrogencarbonate, and extracted with chloroform. 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, and the resulting residue was purified through silica gel column chromatography (eluent—hexane:ethyl acetate=30:1→10:1) to obtain 774 mg (yield 80%) of 3-amino-2,4-bis(isopropylthio)-6-methylpyridine as a yellow oil. Triethylamine (336 mg, 3.32 mmol) was added to a THF (10 ml) solution of this aminopyridine (774 mg, 3.02 mmol), and bromoacetyl bromide (732 mg, 3.62 mmol) was then slowly added thereto dropwise while being cooled with ice, and the mixture was stirred for 17 hours. The reaction mixture was filtered, and the filtrate was concentrated. Then, the residue was purified through silica gel chromatography (eluent—hexane:ethyl acetate=10:1) to obtain 595 mg (yield 52%) of 2-bromo-N-[2,4-bis(isopropylthio)-6-methyl-3-pyridyl]acetamide as a colorless powdery crystal. sodium hydrogencarbonate (29 mg, 0.35 mmol) was added to an acetonitrile (5 ml) solution of this amide (132 mg, 0.35 mmol) and 2-mercaptobenzoxazole (53 mg, 0.35 mmol), and the mixture was stirred at room temperature for 28 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:benzen=6:1) to obtain 69 mg (yield 44%) of the desired compound as a colorless powdery crystal.

Provenance & Evidence