Hydroquinone → 4-Methyl-3a,4,5,7a-tetrahydro-2-benzofuran-1,3-dione

Beteiligte Stoffe

Reaktionsschritte

Maleic anhydride (68.6 parts) and 70 parts of toluene were fed into an autoclave, and melted at 55° C. Then, 0.162 part of hydroquinone was added. Subsequently, 30.9 parts (corresponding to 1.1 moles of trans-1,3-pentadiene per mole of maleic anhydride) of crude trans-1,3-pentadiene composed of 40% of trans-1,3-pentadiene, 20% of cis-1,3-pentadiene and 40% of pentanes was continuously added over 6 hours at 50° C. The temperature was then elevated to 60° C. and the reaction was carried out for 3 hours. After the reaction, the volatile components were removed by distillation at 90° C. under atmospheric pressure. As the Diels-Alder reaction product, 3-methyltetrahydrophthalic anhydride (melting point 61° C.) was obtained in a yield of 99%.

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