METHOD OF SYNTHESIS OF ISOPRENE FROM FORMALDEHYDE AND ISOBUTENE Russian patent published in 2001 - IPC

FIELD: organic chemistry, chemical technology. SUBSTANCE: invention relates to method of synthesis of isoprene based on interaction of formaldehyde and isobutene and/or tert.-butanol. Process is carried out in the presence of acid catalyst and water at increased temperatures for two successive stages. At the first stage synthesis of semiproducts is carried out and at the second stage semiproducts are decomposed in mixture with other components present in reaction mass of the first stage. Reaction products and water are removed from upper part of reactor and isoprene is isolated from products of reaction. Decomposition of semiproducts is carried out in vertical apparatus having heated shell-and-tube zone with 10 tubes, not less, distributed by section in bottom part and reaction zone arranged above and connecting with tube space of shell-and-tube zone and containing liquid. From upper part of indicated reaction zone and/or separation zone connecting with its the forced recirculation of liquid in bottom part of indicated apparatus connecting with tube space is carried out. EFFECT: increased yield of product. 3 cl, 2 dwg, 2 ex