Sulfuric Acid → HCID 21545959, compound

Participants

Reaction Steps

4.7 parts of 4-methylphenylthio fumaric acid, made in analogous manner to part (a) of Example 1, was added in small lots to 20 parts of stirred concentrated sulphuric acid. The solution was allowed to stand for 30 minutes and then it was cautiously poured on to ice. The resulting precipitate was filtered off, washed with water and crystallised from an ethanol/dioxan mixture to give 2.3 parts of 6-methyl-1-thiachromone-2-carboxylic acid, melting point 236°-7°C.

Provenance & Evidence