反応式
[CH2:1]([N:8]1[CH2:13][CH2:12][CH:11]([C:14]([CH:16]2[CH2:21][CH2:20][CH2:19][CH2:18][C:17]2=O)=O)[CH2:10][CH2:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH2:23]([NH:25][NH2:26])[CH3:24].C(#N)C>O>[CH2:23]([N:25]1[C:14]([CH:11]2[CH2:12][CH2:13][N:8]([CH2:1][C:2]3[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=3)[CH2:9][CH2:10]2)=[C:16]2[C:17]([CH2:18][CH2:19][CH2:20][CH2:21]2)=[N:26]1)[CH3:24]参加物
実験手順
The title compound was prepared from the semi-crude (1-benzylpiperidin-4-yl)-(cyclohexanon-2-yl)ketone from step A and 34% aqueous ethylhydrazine in 4:1 acetonitrile and water at room temperature. This provided 8:1 ratio of isomeric ethyl pyrazoles in favor of the title compound. (Note: Use of ethyl hydrazine oxalate in the presence of DIEA gave about 2:1 ratio of the same isomers.) The 1-benzylpiperidine-4-carboxylic acid ethyl ester present in the starting β-diketone was removed after saponification of the crude product with sodium hydroxide in water ethanol mixture followed by extractive work-up. The desired ethyl isomer is the higher Rf isomer. It was isolated on silica gel chromatography (60˜100% ethyl acetate in hexanes and 5˜20% methanol in ethyl acetate, both with 1% triethylamine).
出典と根拠
- ORDレコード
- ord-0f270b078f664919953e4196d1061982
- 出典データセット
- uspto-grants-2002_03
- 特許番号
- US06358979B1
関連ノート
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