4,4-Dimethoxy-2-butanone → 2-Methoxy4-(3-methyl-pyrazol-1-yl)-benzoic acid, methyl ester
Reaction equation
Cl.[NH:2]([C:4]1[CH:13]=[CH:12][C:7]([C:8]([O:10][CH3:11])=[O:9])=[C:6]([O:14][CH3:15])[CH:5]=1)[NH2:3].CO[CH:18](OC)[CH2:19][C:20](=O)[CH3:21]>Cl.O.CO>[CH3:15][O:14][C:6]1[CH:5]=[C:4]([N:2]2[CH:18]=[CH:19][C:20]([CH3:21])=[N:3]2)[CH:13]=[CH:12][C:7]=1[C:8]([O:10][CH3:11])=[O:9]Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 90 °C
Procedure
To a stirred solution of 4-hydrazino-2-methoxybenzoic acid, methyl ester hydrochloride (0.88 g) from Example 104 and one drop of concentrated hydrochloric acid in a 1:1 water/methanol (10 ml) mixture was added acetylacetaldehyde dimethylacetal (0.53 g). The reaction was heated to 90° C. for 5 minutes. The reaction was concentrated in vacuo and partitioned between 1 N sodium hydroxide (10 ml) and ethyl acetate (50 ml). The organic phase was removed and washed with brine, dried over anhydrous magnesium sulfate and filtered. Evaporation of the solvent in vacuo afforded a brown oil which was combined with a previous lot (0.54 g) and recrystallized three times from diisopropyl ether to give 2-methoxy-4-(3-methyl-pyrazol-1-yl)-benzoic acid, methyl ester (0.5 g). m.p. 167-169° C., MS, m/z: 246 (M)+.
Workup
- concentrationThe reaction was concentrated in vacuo
- custompartitioned between 1 N sodium hydroxide (10 ml) and ethyl acetate (50 ml)
- customThe organic phase was removed
- washwashed with brine
- dry with materialdried over anhydrous magnesium sulfate
- filtrationfiltered
- customEvaporation of the solvent in vacuo
- customafforded a brown oil which
- customrecrystallized three times from diisopropyl ether
Sources & evidence
- ORD record
- ord-40a686c94c3a40668e44a412be37f471
- Source dataset
- uspto-grants-2004_12
- Patent number
- US06831079B1
Reaction notes
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