Sodium Hydroxide → 5-Chloropyrazinoic acid

Participants

Reaction Conditions

Reaction Steps

Dissolve 5-chloro-pyrazine-2-carboxylic acid methyl ester (10.0 g, 57.9 mmol) in THF (65 mL) and MeOH (65 mL). Cool the solution to 0° C. before adding 1N NaOH (63.7 mL) with stirring. Warm the mixture to room temperature and stir for 5 h. Concentrate the mixture in vacuo to 1/3 volume. Quench with 1N HCl (75 mL) to form a white precipitate. Dilute with CH2Cl2 (200 mL) and filter. Wash the filter cake with water and CH2Cl2. Separate the phases, dry the organic phase over MgSO4, filter, and concentrate. Add the aqueous layer to the concentrated organic residue and concentrate. Purify by silica gel flash column chromatography, eluting with 40% ethyl acetate/n-hexane, followed by 10% MeOH, 3% acetic acid and 87%

Provenance & Evidence