Oxygen → 2-Methyl-5-methyleneadipic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a mechanically stirred solution of 2 moles of hydroxyquinone dissolved in 3 moles of methacrylic acid at 120° C. and atmospheric pressure was added dropwise (30 min) 1 mole of methylacrylic acid anhydride and the mixture was maintained at 120° C. with stirring for additional 4 hrs (NMR analysis). Throughout the course of the reaction 8% oxygen was admitted to the system. At the end of the reaction, the methacrylic acid was recovered by distillation under reduced pressure (110° C. and 200 mmHg), and the unreacted excess hydroquinone was precipitated out by the addition of toluene (1 liter) to the reaction mixture. A low level (1-2%) of the monomer 2-methyl-5-methylenehexanedioic acid was formed. This monomer was separated from the mixture by a washing step with distilled water. After phase separation, the desired 4-hydroxyphenyl methacrylate was obtained at 97% yield by the distillation of toluene under reduced pressure. {mp. (Uncorrected) 120° C.; Anal. Calcd. For C10H10O3: C, 67.41: H, 5.66; O, 26.94. Found: C, 67.37; H, 5.62}.

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