Triethylamine → Tert-butyl n-heptyl-n-[2-[4-[2-(7-trifluoromethylbenzoxazol-2-ylthio)ethyl]piperazin-1-yl]ethyl]carbamate

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Reaction Steps

To a solution of this alcohol (500 mg, 1.35 mmol) in THF (10 ml) were added triethylamine (180 mg, 1.78 mmol) and 4-(dimethylamino) pyridine (16 mg, 0.13 mmol), and then methanesulfonyl chloride (190 mg, 1.66 mmol) was dropped there into with ice-cooling and stirred for 20 minutes. Further, to the same solution were added triethylamine (45 mg, 0.44 mmol) and methanesulfonyl chloride (45 mg, 0.39 mmol) was dropped thereinto with ice-cooling and stirred for 1 hour. The reaction solution was filtered and the filtrate was concentrated in vacuo. The resulting residue was dissolved in DMF (3 ml), and the resulting solution was dropped into a solution of 2-mercapto-7-trifluoromethylbenzoxazole (310 mg, 1.41 mmol) and potassium carbonate (280 mg, 2.03 mmol) in DMF (7 ml) and stirred at 80° C. for 90 minutes. The reaction solution was concentrated in vacuo and the resulting residue was filtered off with ether. The filtrate was concentrated in vacuo and the resulting residue was purified by a silica gel column chromatography (silica gel 35 g, developing solvent; hexane:acetone=10:1) to provide 283 mg (yield 37%) of tert-butyl N-heptyl-N-[2-[4-[2-(7-trifluoromethylbenzoxazol-2-ylthio)ethyl]piperazin-1-yl]ethyl]carbamate as pale yellow oil.

Provenance & Evidence