ChemicalBook CAS DataBase List 4-HYDROXY-2-METHYLBENZOIC ACID 98

4-HYDROXY-2-METHYLBENZOIC ACID 98 synthesis

11synthesis methods

Product Name:4-HYDROXY-2-METHYLBENZOIC ACID 98
CAS Number:578-39-2
Molecular formula:C8H8O3
Molecular Weight:152.15

6245-57-4

578-39-2

General procedure for the synthesis of 4-hydroxy-2-methylbenzoic acid from 4-methoxy-2-methylbenzoic acid: boron tribromide (20 mmol, 5 g, 10 eq.) was slowly added to a solution of 4-methoxy-2-methylbenzoic acid (2 mmol, 0.332 g) in dichloromethane (20 mL) under argon protection. The reaction mixture was stirred at room temperature until high performance liquid chromatography (HPLC) analysis showed complete consumption of the feedstock. Subsequently, 0.1 M hydrochloric acid (20 mL) was added to the reaction system to quench the reaction and the insoluble material was removed by filtration. The aqueous phase was concentrated under reduced pressure and the residue was dissolved in methanol and concentrated again under reduced pressure to remove the solvent. This dissolution-concentration process was repeated three times, resulting in purified 4-hydroxy-2-methylbenzoic acid as a yellow solid (0.24 g, 80% yield).

6245-57-4
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578-39-2
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Yield:578-39-2 80%

Reaction Conditions:

with boron tribromide in dichloromethane

Steps:

14
4-Hvdroxy-2-methyl-benzoic acid: BBr₃ (20 mmol, 5g, 10 eq.) was added to a solution of 4-methoxy-2-methyl benzoic acid (2 mmol, 0.332g) in DCM (20 ml) and the mixture was stirred under argon until HPLC indicated no starting material remained. HCI (0.1 M, 20 ml) was added and the mixture was filtered. The aqueous layer was evaporated then dissolved in methanol. The solvent was evaporated. The EPO dissolution/evaporation protocol was repeated a further 3 times and gave the pure product as a yellow solid (0.24g, 80%).

References:

MEDIVIR UK Ltd;PEPTIMMUNE, Inc WO2006/64286, 2006, A1 Location in patent:Page/Page column 93-94

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