反应详情

温度

0 °C

The diacid (Example 3) (3.954 g, 8.04 mmoles) was dissolved in 250 mL CH2Cl2 :CH3CN 4:1. Triethyl amine (2.5 mL, 2.2 equiv.) was added followed, at 0° C., by 2-chloro-1-methylpyridinium iodide (2.257 g, 1.1 equiv.). After stirring 1 hour at 0° C., ammonia was added and the mixture stirred for another hour at 10° C. Water was then added and the aqueous layer acidified to pH 5. Extraction with CH2Cl2 (2×) and EtOAc (2×) and flash chromatography of the residue on silica with acetone: CH2Cl2 :AcOH 40:60:1 and 50:50:1 afforded the title compound.

1. stirringthe mixture stirred for another hour at 10° C
2. extractionExtraction with CH2Cl2 (2×) and EtOAc (2×) and flash chromatography of the residue on silica with acetone: CH2Cl2 :AcOH 40:60:1 and 50:50:1