Cinnamoylbenzene → 3,5-diphenyl-4,5-dihydro-1H-pyrazole

HRID 1606035Notes

Reaction equation

HRID 1606035 reaction equation
[CH:1](=[CH:8][C:9]([C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1)=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.O.[NH2:18][NH2:19]>CO>[C:2]1([C:1]2[CH2:8][CH:9]([C:11]3[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=3)[NH:19][N:18]=2)[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 7189CinnamoylbenzeneHCID 24654Hydrazine hydrate (1:1)

Product 1

HCID 36838443,5-diphenyl-4,5-dihydro-1H-pyrazole

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

Benzalacetophenone (12.5 parts) is reacted with hydrazine hydrate (3.1 parts by volume) in methanol to form 3,5-diphenyl-2-pyrazoline. Panasol AN-2 (30 ml), nitrobenzene (7.4 parts) and 5% palladium on carbon catalyst (2 parts) are then added and the mixture heated. Following the distillation of methanol and water from the reaction mixture, the temperature is raised to 200°C. and held at that temperature for 24 hours. The mixture is then cooled to 50°C., filtered, and the catalyst bearing cake of 3,5-diphenylpyrazole is 79.5%, m.p. 194°C. to 199°C.

Sources & evidence

ORD record
ord-fa1f30dd8f4645cdbe49985f08ed62f6
Source dataset
uspto-grants-1976_04
Patent number
US03952010

Reaction notes

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