ChemicalBook CAS DataBase List 4-Chloro-3-hydroxybenzoic acid

4-Chloro-3-hydroxybenzoic acid synthesis

4synthesis methods

Product Name:4-Chloro-3-hydroxybenzoic acid
CAS Number:34113-69-4
Molecular formula:C7H5ClO3
Molecular Weight:172.57

Ethanamine, N-[(3,5-dichlorophenyl)methylene]-2,2-diethoxy-

1000210-73-0
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34113-69-4
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Yield: 90%

Reaction Conditions:

Stage #1:3-methoxy-4-chlorobenzoic acid allyl ester with boron tribromide in dichloromethane at 0 - 20; for 18 h;
Stage #2: with ammonia in dichloromethane;water at 20; for 1.5 h;
Stage #3: with hydrogenchloride in dichloromethane;water; pH=1

Steps:

39
Boron tribromide (1M in dichloromethane, 31 mL, 31.504mmol) was added to an ice-cooled solution of the product of preparation 38 (3.56g, 15.752mmol) in dichloromethane (3OmL) and the mixture was stirred at O⁰C to room temperature for 18 hours. The reaction was quenched with 0.88 ammonia solution and stirred at room temperature for 90 minutes. The reaction mixture was acidified to pH 1 by dropwise addition of 2N hydrochloric acid (aq) and extracted with diethyl ether (2x50mL). The combined organic layers were dried over sodium sulfate and concentrated in vacuo to afford the title compound as a pale yellow solid in 90% yield, 2.45g. ¹HNMR(400MHz, CD₃OD) δ: 7.36-7.38(d, 1H), 7.44-7.47(dd, 1H), 7.54-7.55(d, 1H); LRMS APCI m/z 171 [M-H]-

References:

Location in patent:Page/Page column 53