反应详情

温度

2.5 °C

A solution of 4-(3-methyl-4-nitro-phenoxy)-piperidine-1-carboxylic acid tert-butyl ester (example 43, step 1, 41.9 g, 1.0 eq.) and diethyloxalate (18.77 mL, 1.1 eq.) in tetrahydrofuran (241.7 mL) was dropped into a cold (0-5° C.) solution of potassium tert-butylate (28.54 g, 2.0 eq.) and ethanol (43.64 mL, 6.0 eq.) in tetrahydrofuran (1.022 L). The mixture was stirred for 3 h at 0-5° C. and for 18.5 h at room temperature, poured into 1M hydrochloric acid solution. The aqueous phase was extracted 3 times with tert-butylmethylether and the combined organic phases were washed with brine, dried over sodium sulfate, filtered, evaporated to dryness in vacuo and crystallized from ethanol to yield 44.09 g (81%) as white crystals. MS (m/e): 436.2 (M, 5%).

1. extractionThe aqueous phase was extracted 3 times with tert-butylmethylether
2. washthe combined organic phases were washed with brine
3. dry with materialdried over sodium sulfate
4. filtrationfiltered
5. customevaporated to dryness in vacuo
6. customcrystallized from ethanol
7. customto yield 44.09 g (81%) as white crystals