Other

Vitaly Vasilievich Orlyansky

Anatoly I Lukashov

Alexandr P Khardin

Valentin M Belyaev

Boris Nikolaevich Gorbunov

Boris N Gorbunov

Lidia Vladimirovna Erokhina

Vladimir L Rudkovsky

Galina Dmitrievna Efremova

Daniil Iosifovich Valdman

Ljudmila V Shpantseva

Evgeny Maximovich Kukartsev

Ideya Antonovna Churikova

Pavel Y Gokhberg

The method of preparing isoprene and isoamylenes consists in that a gaseous mixture of isobutylene and methyl alcohol is brought in contact with a catalyst, namely aluminum oxide or tantalum pentoxide, at a temperature of 250 to 500.degree. C. It is recommendable that use should be made of aluminum oxide modified with an oxide of at least one of the following elements: molybdenum, tungsten, chromium, zirconium, titanium, vanadium, and cobalt. Moreover, it is possible to use aluminum oxide modified with a sulphate of at least one of the following elements: zirconium and chromium. A combination of both modifications is also possible. The yield of isoprene obtained by the proposed method is 16 to 20 mol. percent, with respect to the passed methyl alcohol, and the yield of isoamylenes is 25 to 30 mol. percent.

Method of preparing isoprene and isoamylenes

The method of preparing 4,4-dimethyldioxane-1,3 consists in the interaction of isobutylene and formaldehyde in an aqueous medium at from 90.degree. to 115.degree. C in the presence of a catalyst, the capacity of which such inorganic salts of mineral acids may be used with the pH value of the aqueous solutions whereof being within 2.2 to 4.5, resulting in the formation of an organic and an aqueous phase containing the end product, followed by the separation of said phases, washing the organic phase with water, and isolation of the end product. When a catalyst of such salts is used, the acidity of the aqueous solutions of which is either invariable or decreases with an increase in the salt concentration, it is expedient that the aqueous phase and the wash water be evaporated to a level of from 85 to 90 percent to form a fraction containing the unreacted formaldehyde, and a distillation residue which is in fact an oil bed and a salt bed with the latter, after having been separated, being returned to the stage of interaction of the starting reagents.

Method of preparing 4,4-dimethyldioxane-1,3

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Volzhsky Volgogradskoi oblasti, undefined

Vitaly Vasilievich Orlyansky