Hydrazine hydrate (1:1) → 4-{[2-methyl-3-(trifluoromethyl)phenyl]methyl}-1H-pyrazole-3,5-diamine
Reaction equation
[CH3:1][C:2]1[C:7]([C:8]([F:11])([F:10])[F:9])=[CH:6][CH:5]=[CH:4][C:3]=1[CH2:12][CH:13]([C:16]#[N:17])[C:14]#[N:15].O.[NH2:19][NH2:20]>C(O)C>[CH3:1][C:2]1[C:7]([C:8]([F:9])([F:10])[F:11])=[CH:6][CH:5]=[CH:4][C:3]=1[CH2:12][C:13]1[C:16]([NH2:17])=[N:19][NH:20][C:14]=1[NH2:15]Participants
Procedure
To a mixture of malononitrile (2.352 g, 35.6 mmol) in 95% Ethanol (50 mL) was added 2-methyl-3-(trifluoromethyl)benzaldehyde (6.7 g, 35.6 mmol). The reaction was stirred at rt for 18 h. Additional EtOH (20 mL) was added and the mixture was stirred for 20 minutes and cooled to 0° C. in an ice bath. Sodium borohydride (0.364 g, 9.61 mmol) was introduced to the vigorously stirred mixture and the reduction was complete in about 10 min. To the reaction mixture was added water (40 mL). 1N HCl was added in to quench the excess hydride. More water was added in until precipitation was complete. Filtration gave {[2-methyl-3-(trifluoromethyl)phenyl]methyl}propanedinitrile (6.5 g, 77%). To a mixture of {[2-methyl-3-(trifluoromethyl)phenyl]methyl}propanedinitrile (6.5 g, 27.3 mmol) in Ethanol (80 mL) was added hydrazine hydrate (2.68 mL, 54.6 mmol). The reaction mixture was heated at reflux temperature for 8 h. The reaction mixture was concentrated. The crude material was purified on a silica column (eluting with MeOH/DCM: 0˜10%) to give the product (3.5 g, 47%). 1H NMR (400 MHz, METHANOL-d4) δ ppm 2.47 (s, 3H) 3.69 (s, 2H) 7.11-7.37 (m, 2H) 7.51 (d, 1H); LC/MS: MS (ES+) m/e 271.2 [M+H]+.
Workup
- temperatureThe reaction mixture was heated
- temperatureat reflux temperature for 8 h
- concentrationThe reaction mixture was concentrated
- customThe crude material was purified on a silica column (eluting with MeOH/DCM: 0˜10%)
Sources & evidence
- ORD record
- ord-88525badefc543808d69536ccba58410
- Source dataset
- uspto-grants-2015_08
- Patent number
- US09096605B2
Reaction notes
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