Hydrazine hydrate (1:1) → 5-[3-(Cyclopentyloxy)-4-methoxyphenyl]pyrazolidin-3-one
Reaction equation
[CH:1]1([O:6][C:7]2[CH:8]=[C:9]([CH:15]=[CH:16][C:17]=2[O:18][CH3:19])[CH:10]=[CH:11][C:12](O)=[O:13])[CH2:5][CH2:4][CH2:3][CH2:2]1.O.[NH2:21][NH2:22]>C1(C)C=CC=CC=1>[CH:1]1([O:6][C:7]2[CH:8]=[C:9]([CH:10]3[NH:22][NH:21][C:12](=[O:13])[CH2:11]3)[CH:15]=[CH:16][C:17]=2[O:18][CH3:19])[CH2:5][CH2:4][CH2:3][CH2:2]1Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
To a suspension of 3-cyclopentyloxy-4-methoxycinnamic acid (7.9 g, mmol) in toluene (25 ml) is added hydrazine hydrate (2.91 n-A, 60 mmol). The reaction mixture is heated to 100° (bath temperature) for 24 hours. Toluene is partially removed and ether carefully added, and the product allowed to crystallize. The solid is filtered to give crude product (6 g). A crystallization from chlorofom-hexane gives the pure product (5 g) m.p. 185°-186°. 1H NMR (CDCl3) δ 7.02 (1H, s, NH--CO), 6.88 (3H, m, arom), 4.79 (2H, m, carbinolic and benzylic), 4.28 (1H, m, NH), 3.84 (3H, s, CH3O--), 2.79 (2H, d, --CH2CO), 1.9 (5H, m, cyclopentyl C-H), 1.61 (3H, m, cyclopentyl C-H); IR(KBr),3420,3220,3160,2960,1700,1660 cm-1 ; MS m/z 276 (M)+.