Sodium Hydroxide → 2-Chloro-3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonylbenzoic acid

HRID 2167424Notes

Reaction equation

[OH-].[Na+].[Cl:3][C:4]1[C:13]([C:14]2[CH2:18][CH2:17][O:16][N:15]=2)=[C:12]([S:19]([CH3:22])(=[O:21])=[O:20])[CH:11]=[CH:10][C:5]=1[C:6]([O:8]C)=[O:7]>CO>[Cl:3][C:4]1[C:13]([C:14]2[CH2:18][CH2:17][O:16][N:15]=2)=[C:12]([S:19]([CH3:22])(=[O:21])=[O:20])[CH:11]=[CH:10][C:5]=1[C:6]([OH:8])=[O:7]

Participants

Conditions

Temperature: 50 °C

Procedure

A solution of 32.8 g of sodium hydroxide, dissolved in 330 ml of methanol, was slowly added dropwise to a mixture of 170.0 g (0.54 mol) of methyl 2-chloro-3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonylbenzoate and 1 l of methanol at 40-45° C. The suspension was stirred for 5 hours at 50° C. After the solvent had been distilled off, the residue was taken up in 1.5 l of water, and the aqueous phase was extracted three times with ethyl acetate. The aqueous phase was acidified with hydrochloric acid and extracted three times with ethyl acetate. The combined organic phases were subsequently washed to neutrality with water, dried and concentrated. This gave 148.8 g (91% of theory) of 2-chloro-3-(4,5-dihydroisoxazol-3-yl)-4-methylsulfonylbenzoic acid.

Workup

distillationAfter the solvent had been distilled off
extractionthe aqueous phase was extracted three times with ethyl acetate
extractionextracted three times with ethyl acetate
washThe combined organic phases were subsequently washed
customdried
concentrationconcentrated

Sources & evidence

ORD record: ord-c3b6034091fb4f15b2f8b2901183da26
Source dataset: uspto-grants-2015_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09045465B1

Reaction notes

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