Hydrazine hydrate (1:1) → 5-[3-(Cyclopentyloxy)-4-methoxyphenyl]pyrazolidin-3-one

HRID 1655624Notes

Reaction equation

HRID 1655624 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]1

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 2794901HCID 2794901, compound

Product 1

HCID 27279075-[3-(Cyclopentyloxy)-4-methoxyphenyl]pyrazolidin-3-oneYield 60.1%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

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)+.

Workup

  1. temperatureThe reaction mixture is heated to 100° (bath temperature) for 24 hours
  2. customToluene is partially removed
  3. additionether carefully added
  4. customto crystallize
  5. filtrationThe solid is filtered
  6. customto give crude product (6 g)
  7. customA crystallization from chlorofom-hexane

Sources & evidence

ORD record
ord-51c99951db354b35bb11775b007edbee
Source dataset
uspto-grants-1993_10
Patent number
US05250700

Reaction notes

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