Sodium Hydroxide → 6-(4,6-Dimethoxypyrimidin-2-yl)oxy-3-methyl-benzisoxazol-7-carboxylic Acid

HRID 52003Notes

Reaction equation

[CH3:1][O:2][C:3]1[CH:8]=[C:7]([O:9][CH3:10])[N:6]=[C:5]([O:11][C:12]2[CH:21]=[CH:20][C:15]3[C:16]([CH3:19])=[N:17][O:18][C:14]=3[C:13]=2[C:22]([O:24]C)=[O:23])[N:4]=1.[OH-].[Na+]>O>[CH3:10][O:9][C:7]1[CH:8]=[C:3]([O:2][CH3:1])[N:4]=[C:5]([O:11][C:12]2[CH:21]=[CH:20][C:15]3[C:16]([CH3:19])=[N:17][O:18][C:14]=3[C:13]=2[C:22]([OH:24])=[O:23])[N:6]=1

Participants

Conditions

Temperature: 70 °C

Procedure

While heating and stirring 1.0 g of methyl 6-(4,6-dimethoxypyrimidin-2-yl)oxy-3-methylbenzisoxazol-7-carboxylate in 20 ml of N,N-dimethylsulfoxide at 70° C., 1.7 ml of a 2N sodium hydroxide aqueous solution was dropwise added thereto over a period of 10 minutes. Then, the mixture was further heated and stirred at 70° C. for 30 minutes. The mixture was returned to room temperature, then poured into water and extracted with diethyl ether. The aqueous layer was acidified with 10% hydrochloric acid, and precipitated crystals were extracted with ethyl acetate. The organic layer was washed with water and then dried over anhydrous sodium sulfate. It was then concentrated under reduced pressure, and the crystals thereby obtained were washed with isopropyl ether to obtain 0.7 g (yield: 71%) of the desired compound.

Workup

temperatureWhile heating
temperatureThen, the mixture was further heated
customwas returned to room temperature
extractionextracted with diethyl ether
customprecipitated crystals
extractionwere extracted with ethyl acetate
washThe organic layer was washed with water
dry with materialdried over anhydrous sodium sulfate
concentrationIt was then concentrated under reduced pressure
customthe crystals thereby obtained
washwere washed with isopropyl ether

Sources & evidence

ORD record: ord-9131882886ce47d2b7cfe0650bf715a5
Source dataset: uspto-grants-1997_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05616537

Reaction notes

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