反应详情

A mixture of 3-(2-hydroxy-4-methylbenzoyl)benzonitrile (5.78 g; see Example 29), acetic acid (48 g), and a solution of 75% sulfuric acid (48 g) is refluxed for 3 hours. The resulting mixture is diluted with water (100 ml) and extracted with ether (3×75 ml) followed by methylene chloride (2×75 ml). The combined extracts are dried over magnesium sulfate, filtered, and concentrated in vacuo. The residue is chromatographed on silica gel (methylene chloride then hexanes:ether:acetic acid; 50:50:1). The resulting yellow solid is recrystallized from ligroin/isopropyl ether to yield 3-(2-hydroxy-4-methylbenzoyl)benzoic acid (3.62 g), m.p. 198°-215° C.

1. extractionextracted with ether (3×75 ml)
2. dry with materialThe combined extracts are dried over magnesium sulfate
3. filtrationfiltered
4. concentrationconcentrated in vacuo
5. customThe residue is chromatographed on silica gel (methylene chloride
6. customThe resulting yellow solid is recrystallized from ligroin/isopropyl ether