These common heterocyclic compound, 36070-80-1, name is 5-Chloropyrazine-2-carboxylic acid, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. Safety of 5-Chloropyrazine-2-carboxylic acid
Step 2: Preparation of 5-methoxypyrazine-2-carboxylic acid [0171] To a solution 5-chloropyrazine-2-carboxylic acid (7 g, 44.15mmol) in methanol (55 mL) was added concentrated sulphuric acid (0.4 mL) and heated at 65 C for 4 h. The reaction mixture was cooled to room temperature and diluted with methanol (15 mL). Then a solution of sodium methoxide in methanol (8.58 g , 158.94 mmol, 35 mL) was added and the reaction mixture was stirred at room temperature for 30 minutes. Sodium hydroxide (2.825 g , 70.643mmol) in 30 ml water was added into the reaction mixture followed by addition of 40 mL water. Then the reaction mixture was heated at 40 C for 1 h and concentrated to remove methanol. The residue was diluted with water, acidified with 38% aqueous hydrochloric acid solution (pH 2-3) and extracted ethyl acetate (600 mL x 3). The combined organic layer was dried over anhydrous sodium sulfate, filtered and concentrated to afford the title compound 5-methoxypyrazine-2-carboxylic acid (6.43 g, 94% yield) as an orange solid. Calculated M+H: 155.04; Found M+H: 155.1.
The synthetic route of 5-Chloropyrazine-2-carboxylic acid has been constantly updated, and we look forward to future research findings.
Reference:
Patent; MNEMOSYNE PHARMACEUTICALS, INC.; ANDERSON, David R.; VOLKMANN, Robert A.; MENNITI, Frank S.; WO2015/48507; (2015); A1;,
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