4-Bromophenylhydrazine → ethyl 5-amino-1-(4-bromophenyl)-1H-pyrazole-4-carboxylate

反応式

[Br:1][C:2]1[CH:7]=[CH:6][C:5]([NH:8][NH2:9])=[CH:4][CH:3]=1.C(O[CH:13]=[C:14]([C:20]#[N:21])[C:15]([O:17][CH2:18][CH3:19])=[O:16])C>C(O)C.C(OCC)C>[CH2:18]([O:17][C:15]([C:14]1[CH:13]=[N:9][N:8]([C:5]2[CH:6]=[CH:7][C:2]([Br:1])=[CH:3][CH:4]=2)[C:20]=1[NH2:21])=[O:16])[CH3:19]

参加物

実験手順

A solution of 4-bromophenylhydrazine (2.76 g, 14.7 mmol) and ethyl (ethoxymethylene)cyanoacetate (2.50 g, 14.8 mmol) in ethanol (15 mL) was heated at reflux for 2 hours. Upon cooling, a tan precipitate formed. The suspension was diluted with diethyl ether and suction filtered to remove solid. The filtercake was rinsed with diethyl ether and vacuum oven dried to afford 3.20 g (70%) of product as a tan solid: 1H NMR (CDCl3) d 7.79 (s, 1H), 7.64 (d, J=8.7 Hz, 2H), 7.45 (d, J=8.7 Hz, 2H), 5.30 (s, 2H), 4.31 (q, J=7.2 Hz, 2H), 1.37 (t, J=7.2 Hz, 3H) ppm.