Non-a-tocopherols are hydroxymethylated and hydrogenated to produce a-tocopherol in one pot process by simultaneously reacting with paraformaldehyde and hydrogen in the presence of catalysts of benzenesulfonic acid an...Non-a-tocopherols are hydroxymethylated and hydrogenated to produce a-tocopherol in one pot process by simultaneously reacting with paraformaldehyde and hydrogen in the presence of catalysts of benzenesulfonic acid and 5% Pd/C in an autoclave. Effects of various operation conditions have been studied. The preferable reaction conditions are: temperature 180℃ to 200℃, pressure 5.0 MPa, acid concentration 0.5 g/100 ml ethanol, mass ratio of Pd/C to tocopherols 7.1g/100g, and reaction time 5.0 h. A product with a-tocopherol content of 80% was obtained by using a raw material with a total tocopherols content of 80.54%. The conversion of non-a-tocopherols is almost 100%, and the mole yield of a-tocopherol is more than 90%.展开更多
This paper describes the procedures for the facile synthesis of 9,9′-bis(methoxymethyl)fluorene using fluorene as starting material. By hydroxymethylation and etherification reaction, the fluorene can be converted to...This paper describes the procedures for the facile synthesis of 9,9′-bis(methoxymethyl)fluorene using fluorene as starting material. By hydroxymethylation and etherification reaction, the fluorene can be converted to desired products with high yield and purity. The optimum conditions of the synthetic procedures were determined. For hydroxymethylation, the reaction temperature was 13 ℃and the mole ratio of sodium methoxide to paraformaldehyde was 0.26; and for etherification, the reaction temperature was 40 ℃and the reaction time was 15 h. Under the optimum conditions, an overall yield of 580 0 and purity of 99.20 0 were obtained.展开更多
文摘Non-a-tocopherols are hydroxymethylated and hydrogenated to produce a-tocopherol in one pot process by simultaneously reacting with paraformaldehyde and hydrogen in the presence of catalysts of benzenesulfonic acid and 5% Pd/C in an autoclave. Effects of various operation conditions have been studied. The preferable reaction conditions are: temperature 180℃ to 200℃, pressure 5.0 MPa, acid concentration 0.5 g/100 ml ethanol, mass ratio of Pd/C to tocopherols 7.1g/100g, and reaction time 5.0 h. A product with a-tocopherol content of 80% was obtained by using a raw material with a total tocopherols content of 80.54%. The conversion of non-a-tocopherols is almost 100%, and the mole yield of a-tocopherol is more than 90%.
文摘This paper describes the procedures for the facile synthesis of 9,9′-bis(methoxymethyl)fluorene using fluorene as starting material. By hydroxymethylation and etherification reaction, the fluorene can be converted to desired products with high yield and purity. The optimum conditions of the synthetic procedures were determined. For hydroxymethylation, the reaction temperature was 13 ℃and the mole ratio of sodium methoxide to paraformaldehyde was 0.26; and for etherification, the reaction temperature was 40 ℃and the reaction time was 15 h. Under the optimum conditions, an overall yield of 580 0 and purity of 99.20 0 were obtained.
