The invention provides a process for producing a polyphenylene ether by subjecting a 2,6-disubstituted phenol to oxidative coupling by introducing oxygen in the presence of a catalyst system which comprises a manganese compound, a chelant, a base, and an alpha,beta-unsaturated ketone, a beta-diketone, or a vinyl ether. The polyphenylene oxide produced has substantially no amine odor and more stable molecular weight, and is suitable for blending with styrenic or other resins to make thermoplastic resin blends of low odor and good physical properties.
Reversible pH-dependent cyclization of hydroxy-substituted gem-chloronitroso compounds to isoxazoline N-oxides and 5,6-dihydro-4H-1,2-oxazine N-oxides
作者:R. S. Malykhin、A. Yu. Sukhorukov
DOI:10.1007/s11172-024-4247-1
日期:2024.5
Cyclization of hydroxy-substituted gem-chloronitroso compounds under the action of bases affords cyclic nitronates, namely, isoxazoline N-oxides and 5,6-dihydro-4H-1,2-oxazine N-oxides. The process is reversible, viz., the chloronitroso compounds are regenerated upon the action of hydrogen chloride on the cyclization products. A method for the synthesis of cyclic nitronates from aldols using the title