Water → HCID 136014671, compound

HRID 14405Notes

Reaction equation

B(Br)(Br)Br.C[O:6][C:7]1[CH:12]=[CH:11][C:10]([C:13]2[C:17]([C:18]([OH:20])=[O:19])=[C:16]([CH3:21])[S:15][N:14]=2)=[CH:9][CH:8]=1.O.[OH-].[Na+]>ClCCl>[OH:6][C:7]1[CH:8]=[CH:9][C:10]([C:13]2[C:17]([C:18]([OH:20])=[O:19])=[C:16]([CH3:21])[S:15][N:14]=2)=[CH:11][CH:12]=1

Participants

Conditions

Temperature: -78 °C

Procedure

The solution of boron tribromide in dichloromethane (1.0 M, 12.4 mL) in a 100-mL round bottom flask was cooled to −78° C., followed by the addition of 1.03 g of 3-(4-methoxyphenyl)-5-methylisothiazole-4-carboxylic acid as a solid slowly. The reaction mixture was stirred at −78° C. for 2 hrs. and at room temperature overnight. Water (20 mL) was added slowly, followed by the addition of 20 mL of 1.0 N NaOH and 100 mL of dichloromethane. The two layers were separated with a separatory funnel. The aqueous layer was acidified by the addition of concentrated hydrochloric acid. The product was extracted with ethyl acetate (3×100 mL). Solvent was evaporated in vacuo to give 0.935 g of 3-(4-hydroxyphenyl)-5-methylisothiazole-4-carboxylic acid (96%, theoretical yield 0.972 g). LCMS (method B) RT 2.28 min., MH+236. 1H NMR (500 MHz, CD3OD) δ 7.42 (d, J=8.5Hz, 2H), 6.80 (d, J=8.5Hz, 2H), 2.70 (s, 3H).

Workup

customat room temperature
customovernight
customThe two layers were separated with a separatory funnel
additionThe aqueous layer was acidified by the addition of concentrated hydrochloric acid
extractionThe product was extracted with ethyl acetate (3×100 mL)
customSolvent was evaporated in vacuo

Sources & evidence

ORD record: ord-7b79b84bed9f4bfc85fad41e3937811f
Source dataset: uspto-grants-2010_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07732434B2

Reaction notes

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