| 主权项 |
1. A method for the synthesis of a dialkoxy alkane, as a primary reaction product, corresponding to the general formula: RR′CH—O—CRR′—O—CHRR′ in which R and R′ are either H, or a CH3—(CH2)n— radical, n being between 0 and 2 and such that the total number of carbon atoms of the R and R′ radicals is ≦3, said method consists of
selectively oxidizing a part of an amount of a light alcohol comprising from 1 to 4 carbon atoms, in the presence of oxygen and a solid oxidation catalyst in a reaction medium comprising a gas phase containing an acid compound selected from the group consisting of SO3, SO2, and NO2 having, in solution in water, a pKa of less than 6.3, wherein the amount of the acid compound is between 1 and 3000 ppm of the gaseous fraction of the reaction medium, to give an aldehyde, and reacting said aldehyde with the remainder of the amount of the light alcohol to give the dialkoxy alkane, wherein the solid oxidation catalyst is based on molybdenum in oxide form corresponding to the general formula:
Mo12X1aX2bX3cX4dX5eOx wherein Mo=molybdenum; O=oxygen; X1=at least one element selected from the group consisting of iron, nickel, cobalt, manganese, tin, and copper; X2=at least one element selected from the group consisting of bismuth, antimony, tellurium, indium, aluminum, and chromium; X3=at least one element selected from the group consisting of phosphorus, tungsten, titanium, vanadium, tantalum, and niobium; X4=at least one element selected from the group consisting of alkaline-earth metals, lanthanum, and cerium; X5 is at least one element selected from the group consisting of alkali metals; and a, b, c, d and e are indices, the values of which are 0≦a≦20; 0≦b≦4; 0≦c≦5; 0≦d≦2; 0≦e≦2 such that a+b>0; and x is a numerical value determined by the degree of oxidation of the other elements, and optionally comprising silicon, wherein the oxidation reaction is carried out by contact in the vapor phase at a temperature between 100 and 350° C., under a pressure between 100 and 500 kPa with a space velocity for the introduction of the reaction mixture of between 2000 and 100 000 h−1. |
