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Immobilized poly(ethylene glycol) (PEG 600-PS) was used as an effective phase-transfer catalyst for the synthesis of hydroxypivaldehyde from isobutyraldehyde (IBA) and formaldehyde in the presence of an inorganic base. Studies on the influence of the parameters on the course of the reaction in a batch reactor showed that the use of the PEG 600-PS catalyst allowed one to obtain HPA with high efficiency (IBA conversion >96%, selectivity >98%) in a relatively short time and under mild conditions (2 h, 40 °C). The developed method enables easy separation of the post-reaction mixture by simple phase separation, and the immobilized catalyst can be separated by filtration and then used five times without a loss in its activity. The high activity and stability of the catalyst was also confirmed in a test carried out in a flow reactor. [ABSTRACT FROM AUTHOR]

Neopentyl glycol (NPG) is a precursor for the manufacture of many valuable products of industrial importance such as polyester, polyurethane and alkyd resins, synthetic lubricants, hydraulic fluids, drugs, etc. The structure of NPG provides the resins with excellent hydrolytic stability, resistance to weather conditions, good flexibility-hardness balance, and outstanding functional properties. The paper presents a literature review on the development of methods for NPG preparation, focusing primarily on the synthesis of NPG by hydrogenation of hydroxypivaldehyde, which is obtained by the crossed aldol condensation of isobutyraldehyde and formaldehyde. Preparation of the substrates, catalysts, technical and apparatus solutions, and NPG purification were discussed. [ABSTRACT FROM AUTHOR]