ChemicalBook CAS DataBase List 5-bromo-4-nitrothiophene-2-carboxylic acid

5-bromo-4-nitrothiophene-2-carboxylic acid synthesis

5synthesis methods

Product Name:5-bromo-4-nitrothiophene-2-carboxylic acid
CAS Number:89283-24-9
Molecular formula:C5H2BrNO4S
Molecular Weight:252.04

2160-52-3 Synthesis

ethyl 5-bromo-4-nitrothiophene-2-carboxylate

2160-52-3
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5-bromo-4-nitrothiophene-2-carboxylic acid

89283-24-9
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Yield:89283-24-9 83.35%

Reaction Conditions:

with lithium hydroxide monohydrate;potassium hydroxide in ethanol at 15; for 1 h;Inert atmosphere;

Steps:

1

A mixture of ethyl 5-bromo-4-nitro-thiophene-2-carboxylate (2 g, 7.14 mmol, 1 eq), (0166) KOH (801.24 mg, 14.28 mmol, 2eq) in EtOH (20 mL) and (10 mL) was degassed and purged with N? for 3 times, and then the mixture was stirred at 15 °C for 1 hr under Na atmosphere. The reaction was monitored by LCMS which showed complete consumption of reactant and defection of the desired mass peak. The reaction mixture was concentrated under reduced pressure. The reaction mixture was partitioned between HCi (50 ml, 1 N) and EtOAc (50 mL x 2). The organic phase was separated, washed with brine (50 mL), dried over anhydrous filtered and concentrated under reduced pressure to give a residue. The residue was purified by column chromatography ( Petroleum ether / Ethyl acetate ~ 50/1 to 0/1) to afford 5-bromo-4- nitro-thiophene-2 -carboxylic acid (1 .5 g, 5.95 mmol, 83.35% yieid) as a white solid.

References:

WO2022/76589,2022,A1 Location in patent:Page/Page column 76

5751-83-7 Synthesis