ChemicalBook CAS DataBase List 1-Methyl-1H-pyrazole-3-carboxylic acid

1-Methyl-1H-pyrazole-3-carboxylic acid synthesis

4synthesis methods

Product Name:1-Methyl-1H-pyrazole-3-carboxylic acid
CAS Number:25016-20-0
Molecular formula:C5H6N2O2
Molecular Weight:126.11

methyl 1-methyl-1H-pyrazole-3-carboxylate

17827-61-1
105 suppliers
$17.00/250mg

25016-20-0
210 suppliers
$9.00/100mg

Yield:25016-20-0 98%

Reaction Conditions:

with lithium hydrochloride monohydrate in tetrahydrofuran;methanol;water at 0 - 30; for 3 h;

Steps:

99.2

Step 2: To a solution of step 1 intermediate (7.0 g, 50 mmol) in a mixture of THF (20 mL) and MeOH (20 mL) was added a solution of LiOH H₂0 (4.2 g, 100 mmol) in water (20 mL) at 0°C. The RM was stirred at rt for 3 h. The RM was concentrated and subsequently diluted with water. The aqueous layer was acidified with sat. NaHS0₄ solution up to pH~4-5 and extracted with EtOAc. The combined organic layers were dried and concentrated under reduced pressure to yield the desired product (6.2 g, 98%). LC-MS (Method 3): m/z [M+H]⁺ = 127.2 (MW calc. 126.11); R, = 0.44 min.

References:

WO2015/22073,2015,A1 Location in patent:Page/Page column 90; 91