ChemicalBook CAS DataBase List 4-FLUORO-2-HYDROXYBENZOIC ACID

4-FLUORO-2-HYDROXYBENZOIC ACID synthesis

15synthesis methods

Product Name:4-FLUORO-2-HYDROXYBENZOIC ACID
CAS Number:345-29-9
Molecular formula:C7H5FO3
Molecular Weight:156.11

1583-58-0 Synthesis

1583-58-0
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$6.00/5g

345-29-9
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$10.00/1g

Yield:345-29-9 90%

Reaction Conditions:

with sodium hydroxide in dimethyl sulfoxide at 130; for 8 h;

Steps:

1.1 First step: Preparation of 4-fluorosalicylic acid

Dimethyl sulfoxide (DMSO, 4 L) was added to a dry 10 L four-necked flask,2,4-Difluorobenzoic acid (500 g, 3.16 mol)And NaOH (253 g, 6.32 mol),And warmed to 130 , the reaction for about 8h,TLC detection,Until the reaction is complete, the reaction system was reduced to room temperature,The reaction solution was slowly poured into 40L ice water,With concentrated hydrochloric acid to adjust the pH to 2 ~ 3 (adjust the temperature of the process is not higher than 20 )A large number of solid precipitation, continue stirring 2h suction filtration, the filter cake was washed with an appropriate amount of water,Obtained as a white solid, dried at 60 ° C for 12h under reduced pressure to give 4-fluorosalicylic acid 450g, yield 90%.mp 184.9 ~ 185.2 ° C.

References:

CN107501260,2017,A Location in patent:Paragraph 0030; 0031; 0033; 0034

456-22-4 Synthesis