| abstract |
A method for industrially advantageously obtaining high purity 4,4'-dihydroxydiphenyl sulfone monoether. Wherein R 1 and R 2 are each independently halogen, alkyl having 1 to 8 carbons or alkenyl having 2 to 8 carbons; m and n are each independently integers of 0-4; R 3 Is an alkyl having 1 to 8 carbons, alkenyl having 2 to 8 carbons, cycloalkyl having 3 to 8 carbon atoms, or an optionally substituted aralkyl). adjust pH, (2) remove excess alkyl halides, (3) use solvents such as water with an ionic content of 0.05 ppm or less, (4) use containers coated internally with anticorrosive layers, ( 6) adding chelating agents, and (7) using means to dry by mechanical stirring:n n n [Formula I] |