[C:1]([NH:9][N:10]=[CH:11]/[CH:12]=[CH:13]/[CH3:14])(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[N:4][CH:3]=1>C1(C2C=CC=CC=2)C=CC=CC=1.CCOCC>[C:1]([N:9]1[CH:13]([CH3:14])[CH2:12][CH:11]=[N:10]1)(=[O:8])[C:2]1[CH:7]=[CH:6][CH:5]=[N:4][CH:3]=1Nineteen grams of this hydrazone was suspended in 50 ml of biphenyl ether, followed by stirring at 200°-220° C. (bath temperature) for 3 hours. After cooling, the reaction liquid was purified by silica gel chromatography (CHCl3 :MeOH=100:1). Thus there was obtained 8.0 g of 1-nicotinoyl-5-methyl-2-pyrazoline in the form of an oil (bp. 143°-145° C./0.3 mmHg). The yield was 42.1%.
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