METHOD OF PREPARING SUBSTITUTED ACROLEINS Russian patent published in 1998 - IPC

FIELD: chemical industry. SUBSTANCE: present invention describes method of aldol condensation and dehydration for conversion of aldehyde, e.g. valeric aldehyde, to substituted acrolein, e.g. propylbutyl acrolein (2-propyl hept-2-enal). Adol condensation and dehydration are carried out in stirred reactor using alkali catalyst such as sodium hydroxide using sodium hydroxide. Stream of reaction product comprising both organic and aqueous phases, distilled in column to give heterogeneous azeotrope containing water and aldehyde. During condensation and separation of phases, lower aqueous layer is recovered from setup without having to carry out neutralization, from lower area of distillation zone, mixture of substituted aerolein and alkaline catalyst solution. Substituted acrolein is recovered as product, whereas catalyst solution is recycled into aldol condensation reactor. Some catalyst is removed to regulate degree of formation of Kanniciaro reaction products. EFFECT: more efficient preparation method. 26 cl, 8 tbl