4-Toluenesulfonyl chloride → HCID 87467096, compound

Participants

Reaction Steps

A mixture of 3,5-dibromopyridine (23.60 g, 100.0 mmol), 4-penten-2-ol (10.8 g, 125.0 mmol), palladium(II) acetate (230 mg, 1.02 mmol), tri-o-tolylphosphine (1.20 g, 3.94 mmol), triethylamine (29.7 mL, 213.45 mmol), and acetonitrile (40 mL) was heated in a sealed glass tube at 140° C. for 14 h. The reaction mixture was cooled to ambient temperature, diluted with water, and extracted with chloroform (3×200 mL). The combined chloroform extracts were dried over sodium sulfate and filtered. Removal of solvent by rotary evaporation, followed by column chromatography over silica gel eluting with acetone-chloroform (1:9, v/v) furnished 8.10 g (34.0%) of a pale-yellow oil. (4E)-N-Methyl-5-(5-bromo-3-pyridyl)-4-penten-2-amine To a stirring solution of (4E)-5-(5-bromo-3-pyridyl)-4-penten-2-ol (3.14 g, 13.0 mmol) in dry pyridine (30 mL) at 0° C. was added p-toluenesulfonyl chloride (3.71 g, 19.5 mmol). The reaction mixture was stirred for 24 h at ambient temperature. The pyridine was removed by rotary evaporation. Toluene (50 mL) was added to the residue and subsequently removed by rotary evaporation. The crude product was stirred with a saturated solution of sodium bicarbonate (100 mL) and extracted with chloroform (3×100 mL). The combined chloroform extracts were dried over sodium sulfate, filtered, and concentrated by rotary evaporation to give (4E)-5-(5-bromo-3-pyridyl)-4-penten-2-ol p-toluenesulfonate. The resulting tosylate was treated with excess methylamine (40% solution in water), ethyl alcohol (10 mL), and stirred at ambient temperature for 18 h. The resulting solution was extracted with chloroform (3×100 mL). The combined chloroform extracts were dried over sodium sulfate and filtered. Removal of solvent by rotary evaporation followed by column chromatography over silica gel eluting with chloroform-methanol (95:5, v/v) produced 1.50 g (45.0%) of a pale-yellow oil.

Provenance & Evidence