反应详情

温度

182.5 °C

A mixture of 1.40 g of compound (3) and 7.29 g of pyridine hydrochloride was stirred at 180 to 185° C. for 6.5 hours. After cooled to room temperature, the mixture was made basic with aqueous NaHCO3 and then extracted with ethyl acetate. The organic layer was successively washed with water and brine and dried over MgSO4. After the solvent was removed, the obtained oily residue was purified by silica gel chromatography (chloroform:methanol=50/1 to 20/1) to obtain 0.34 g of the oily compound (4). Thus-obtained free compound was crystallized in form of an oxalate and recrystallized from MeOH/Et2O.

1. temperatureAfter cooled to room temperature
2. extractionextracted with ethyl acetate
3. washThe organic layer was successively washed with water and brine
4. dry with materialdried over MgSO4
5. customAfter the solvent was removed
6. customthe obtained oily residue was purified by silica gel chromatography (chloroform:methanol=50/1 to 20/1)