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ChemicalBook CAS DataBase List 3-METHYLPYRAZINE-2-CARBOXYLIC ACID METHYL ESTER
41110-29-6

3-METHYLPYRAZINE-2-CARBOXYLIC ACID METHYL ESTER synthesis

2synthesis methods
-

Yield: 87%

Reaction Conditions:

with sulfuric acid at 0 - 60; for 4 h;Inert atmosphere;

Steps:

A Step A:
Methyl 3-methylpyrazine-2-carboxylate.

To a solution of 3-methylpyrazine-2-carboxylic acid (6 g, 43.4 mmol, 1 equiv) in methanol (60 mL) at 0° C. was added H2SO4 (2.9 mL, 54.3 mmol, 1.25 equiv) dropwise, and the reaction mixture was stirred at 60° C. for 4 h.
The solvent was evaporated, and the residue was dissolved in water (5 ml) and basified with a 10% aq. Na2CO3 solution to pH 12.
The solution was extracted with AcOEt.
The combined organic layers were dried over MgSO4, filtered and the solvents evaporated under vacuum to give the title compound (5.75 g, 37.8 mmol, 87%), which was used in the next step without further purification. 1H NMR (300 MHz, CDCl3) δ 8.61 (s, 1H), 8.51 (s, 1H), 4.01 (s, 3H), 2.85 (s, 3H).

References:

JANSSEN PHARMACEUTICA NV;GELIN, Christine US2020/392155, 2020, A1 Location in patent:Paragraph 0172; 0209-0210

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