ChemicalBook CAS DataBase List 5-CHLORO-PYRAZINE-2-CARBOXYLIC ACID

5-CHLORO-PYRAZINE-2-CARBOXYLIC ACID synthesis

8synthesis methods

Product Name:5-CHLORO-PYRAZINE-2-CARBOXYLIC ACID
CAS Number:36070-80-1
Molecular formula:C5H3ClN2O2
Molecular Weight:158.54

33332-25-1 Synthesis

33332-25-1
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36070-80-1
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Yield:36070-80-1 96%

Reaction Conditions:

with potassium carbonate in tetrahydrofuran;water at 25; for 42 h;

Steps:

29
Example 29 5- [2 (R)- (3-CHLORO-4-METHANESULFONYL-PHENYL)-3-CYCLOPENTYL-PROPIONYLAMINO]- PYRAZINE-2-CARBOXYLIC acid HYDROXYAMIDE [000197] A solution of methyl 5-chloropyrazine-2-carboxylate (30.00 g, 0.17 mol) in tetrahydrofuran (87 mL) was treated with a solution of potassium carbonate (72.08 g, 0.52 mol) in water (261 mL). The resulting reaction mixture stirred at 25°C for 42 h. The reaction mixture was then acidified to a pH of about 2 with concentrated hydrochloric acid, diluted with a saturated aqueous sodium chloride solution (300 mL), and was continuously extracted with ethyl acetate (4L total) until no product was present in the aqueous layer. The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo to afford 5-chloro-pyrazine-2-carboxylic acid (26.54 g, 96%) as an off-white solid: mp 150-151°C ; EI-HRMS m/e calcd for CSH3CIN202 (M 157.9883, found 157.9877.

References:

F. HOFFMANN-LA ROCHE AG WO2004/52869, 2004, A1 Location in patent:Page 115 - 116

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34604-60-9 Synthesis