反应详情

To a mixture of 5-methyl-6-sulfo-pyridine-2-carboxylic acid (0.8 g, 3.69 mmol) in methanol (20 mL) was added 4 N hydrogen chloride in dioxane (8 mL). The mixture was stirred overnight at room temperature. Undissolved solid was filtered off, and the filtrate was concentrated to give the product as yellow solid 0.5 g; MS (EI): m/e=232.0 [M+H]+.

1. filtrationwas filtered off
2. concentrationthe filtrate was concentrated