Methacrylic Acid → HCID 18431813, compound

Participants

Reaction Conditions

Reaction Steps

In a 2 l 5 neck round bottled flask equipped with nitrogen inlet, 250 ml pressure equalized addition funnel, reflux condenser, thermometer, and mechanical stir was added 1 Kg polyphosphoric acid (Aldrich, 84%). The temperature was raised to 100° C., then 180 g-phosphorus pentoxide was added and the temperature was raised to 130° C. Stirring was continued until all the phosphorus pentoxide had dissolved then the flask and contents were cooled to 80° C. A solution containing 79.2 g (455 mmol) 3-phenyl-2-methylthiophene and 40.1 g (465 mmol) methacrylic acid (Aldrich) dissolved in 100 ml dichloromethane was added slowly. Stirring continued with refluxing dichloromethane for 7 h, during which time an additional 130.8 g (1.52M) methacrylic acid in 250 ml dichloromethane was added (in portions, every 1.5 h). The contents of the flask were poured on to ice, the organic layer was collected with 20% dichloromethane in hexane, washed with water, neutralized with a saturated solution of sodium bicarbonate, then again washed with water. The organic fraction was dried over magnesium sulfate, filtered, then the solvents were removed in vacuo. Yield: 71.4 g (65%) (89.32 g dark orange oil, 80% by GC: used in subsequent steps without further purification). The title compound was analysed by 1H-NMR spectroscopy.

Provenance & Evidence