2-Ethoxy-3-methyl-1-butene → Ethyl 1-(2,4-dichlorophenyl)-5-(propan-2-yl)-1H-pyrazole-3-carboxylate
Reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[NH:9][N:10]=[C:11](Cl)[C:12]([O:14][CH2:15][CH3:16])=[O:13].C(O[C:21]([CH:23]([CH3:25])[CH3:24])=[CH2:22])C>C(=O)([O-])[O-].[Na+].[Na+].O>[Cl:1][C:2]1[CH:7]=[C:6]([Cl:8])[CH:5]=[CH:4][C:3]=1[N:9]1[C:21]([CH:23]([CH3:25])[CH3:24])=[CH:22][C:11]([C:12]([O:14][CH2:15][CH3:16])=[O:13])=[N:10]1Participants
5
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 70 °C
Procedure
1550 g of ethyl 2-chloroglyoxalate 2,4-dichlorophenylhydrazone are dissolved in 600 g of 2-ethoxy-3-methylbut-1-ene and 325 g of sodium carbonate, dissolved in 300 ml of water, are added such that a pH of greater than 8.0 is always maintained. After a reaction time of 4 hours (60°-80° C.), the aqueous phase is separated off and 200 ml of hydrochloric acid (pH~1) are added to the organic phase and the mixture is heated to reflux for 1 hour. After cooling to 70° C., the organic phase is separated off and crystallized using methanol/water. 1694 g of product having a purity of 96.3% are obtained, which corresponds to a yield of 94.7% of theory. The melting point is 95°-96° C.
Workup
- additionare added such that a pH of greater than 8.0
- temperatureis always maintained
- customAfter a reaction time of 4 hours (60°-80° C.), the aqueous phase is separated off
- addition200 ml of hydrochloric acid (pH~1) are added to the organic phase
- temperaturethe mixture is heated
- temperatureto reflux for 1 hour
- customthe organic phase is separated off
- customcrystallized
- customare obtained
Sources & evidence
- ORD record
- ord-9bd544e5615344aeb2cfac81095dbfe3
- Source dataset
- uspto-grants-1992_10
- Patent number
- US05159086
Reaction notes
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