反应详情

温度

100 °C

To a solution of 2,6-pyridinedicarboxylate monoethyl ester 1 (1.25 g, 6.40 mmol, 1.00 equiv) and N,N-diisopropylethylamine (2.2 mL, 12.8 mmol, 2.00 equiv) in toluene (38 mL) and tert-butanol (3.8 mL) was added DPPA (1.9 mL, 8.8 mmol, 1.4 equiv). The resulting solution was heated at 100° C. for 5 hr, cooled and partitioned between ethyl acetate and water, washed with brine and dried (sodium sulfate). Purification by chromatography (15% ethyl acetate in hexanes) afforded 6-tert-butoxycarbonylamino-pyridine-2-carboxylic acid ethyl ester (0.88 g, 51%) as a yellow semisolid 348. LCMS: (MH)+=267.1 (rt=1.95 min).

1. temperaturecooled
2. custompartitioned between ethyl acetate and water
3. washwashed with brine
4. dry with materialdried (sodium sulfate)
5. customPurification by chromatography (15% ethyl acetate in hexanes)