METHOD OF ISOPRENE OBTAINING Russian patent published in 2015 - IPC C07C11/18 C07C1/20 C07C2/86 

FIELD: chemistry.

SUBSTANCE: invention relates to method of obtaining isoprene, which includes condensation of isobutylene with water solution of formaldehyde in presence of acid catalyst at temperature 80-110°C, pressure 15-25 atm, separation of reaction mass into oil and water layers, evaporation of water layer, addition of formaldehyde to residue after evaporation of initial water solution and recirculation of obtained mixture into condensation zone, extraction of fraction of 4,4-dimethyl-1,3-dioxane from oil layer with its following liquid-phase decomposition in presence of tertiary butyl alcohol and/or isobutylene into isoprene at increased temperature and pressure. Method is characterised by the fact that supplied to decomposition fraction of 4,4-dimethyl-1,3-dioxane contains from 0.6 to 4.2 wt % of high-boiling by-products.

EFFECT: method makes it possible to reduce power consumption at stage of 4,4-dimethyl-1,3-dioxane extraction.

2 cl, 2 ex