METHOD OF OBTAINING ISOPRENE Russian patent published in 2008 - IPC C07C11/18 C07C2/86 

FIELD: chemistry.

SUBSTANCE: invention relates to the method of obtaining isoprene from isobutylene, which is contained in C₄-fractions of hydrocarbons, and the formaldehyde, carried out at presence of water and the acid catalyst and including the stage of synthesis of half-finished products, the antecedents of isoprene, with their release into the composition of organic and aqueous flows and by distillation from the organic stream of the hydrocarbons C₄, and the stage of decomposition of the obtained half-finished products with the release of the stream, which contains isoprene and its divisions. The method is characterised by the fact that the stage of synthesis is achieved in two steps using in the second stage isobutylene as a raw material, which is isolated after the stage of decomposition from the stream, which contains isoprene, and the aqueous stream after the first stage of synthesis of the remaining part of the organic flow after the first stage of synthesis gets rid of hydrocarbons with a boiling point of less than 135°C and remove the bottom product, hydrocarbons with a boiling point of less than 135°C, and the remaining part of the organic stream after the second step of synthesis and aqueous stream from the second step are directed to the stage of decomposition.

EFFECT: makes it possible to obtain isoprene of high purity without using any special purification methods.

2 cl, 1 dwg, 1 ex