Hydroxylamine → 1,1-Dimethylethyl 4-[4-(4,5-dihydro-5-phenyl-3-isoxazolyl)-2-thiazolyl)-1-piperidinecarboxylate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a suspension of 1,1-dimethylethyl 4-(4-formyl-2-thiazolyl)-1-piperidinecarboxylate (1.0 g, 3.4 mmol) in ethanol (5 mL) was added an aqueous solution of hydroxylamine (50 wt. %, 0.25 mL, 4.0 mmol). The reaction mixture was heated at 60° C. for 1 h, during which time the reaction mixture became homogeneous. The resulting solution was cooled to room temperature and diluted with tetrahydrofuran (10 mL). To the reaction mixture was added styrene (0.57 mL, 5 mmol), followed by portionwise addition of Clorox® aqueous sodium hypochlorite solution (10.5 mL) over 3 h. The reaction mixture was stirred overnight at room temperature, and the resulting solid was filtered, washed with water and diethyl ether, and air dried to give the title compound as a white powder (610 mg). The filtrate was diluted with saturated aqueous sodium bicarbonate solution and extracted with diethyl ether. The extract was dried (MgSO4) and concentrated under reduced pressure to give 850 mg of the title compound as a yellow oil. The oil was diluted with diethyl ether (4 mL) and allowed to stand to give additional 233 mg of the product as a white solid.

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