ChemicalBook CAS DataBase List 1,5-DIMETHYL-1H-PYRAZOLE-3-CARBOXYLIC ACID

1,5-DIMETHYL-1H-PYRAZOLE-3-CARBOXYLIC ACID synthesis

5synthesis methods

Product Name:1,5-DIMETHYL-1H-PYRAZOLE-3-CARBOXYLIC ACID
CAS Number:5744-59-2
Molecular formula:C6H8N2O2
Molecular Weight:140.14

5744-51-4 Synthesis

ETHYL 1,5-DIMETHYL-1H-PYRAZOLE-3-CARBOXYLATE

5744-51-4
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$6.00/1g

1,5-DIMETHYL-1H-PYRAZOLE-3-CARBOXYLIC ACID

5744-59-2
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$8.00/1g

Yield: 81%

Reaction Conditions:

with lithium hydroxide monohydrate in tetrahydrofuran;water at 0; for 1 h;

Steps:

Ethyl 1 ,5-dimethyl-1H-pyrazole-3-carboxylate (2.0 g, 0.01 mol), and Li0H.H₂0 (1.4 g, 0.03 mol) were taken into THF (5 ml_) and water (2 ml_) and stirred at 0 °C for 1 h. The reaction mixture was partitioned between H₂0 (25 ml_) and EtOAc (15 ml_), and the organic extract was discarded. The aqueous layer was acidified to pH 1 - 2 using aqueous HCI (1 M) and the resulting mixture was reextracted with EtOAc (3 x 15 ml_). The combined extracts were dried (Na₂S0₄) and the solvent was removed in-vacuo to give 1 ,5-dimethyl-1H-pyrazole-3-carboxylic acid (Intermediate 31 ) (1 .3 g, 81 %) as a gum.The data for Intermediate 31 are in Table 2.

References:

HEPTARES THERAPEUTICS LIMITED;BROWN, Giles;CONGREVE, Miles;TEOBALD, Barry;FIELDHOUSE, Charlotte;SWAIN, Nigel;PICKWORTH, Mark;BOTTEGONI, Giovanni WO2020/79457, 2020, A1 Location in patent:Paragraph 45

615-79-2 Synthesis