Rearrangements of Hydroperoxides Investigated in Micro Reactors

3 Rearrangements of Hydroperoxides Investigated in Micro Reactors Organic synthesis 82 [OS 82] Rearrangement of cumene hydroperoxide 

The Hock process includes the oxidation of cumene by air to hydroperoxides using large bubble columns and the cleavage of the hydroperoxide via acid catalysis, which is reaction [OS 82]. This process is used for the majority of world-wide phenol production and, as a secondary product, also produces large quantities of acetone [64]. Phenol is used, e.g., for large-scale polymer production when reacted in a polycondensation with formaldehyde. 

The reaction mechanism is based on protonation of the hydroxyl moiety, rearrangement of the phenyl group and simultaneous cleavage of water, creating a carbocation as intermediate [135]. This cation is hydroxylated by water. Thereby, an unstable hemiacetal is formed that splits into two molecules, phenol and water. 

In a typical experiment in a micro reactor, 67 wt.-% technical cumene hydroperoxide was reduced to 1.0 wt.-% [64]. A recycle ratio of 2 was applied. 

Converslon/selectivlty/yleld - benchmarking to conventional apparatus 

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