ISSN:
0959-8103
Schlagwort(e):
bis(chloroformate)
;
cyclization
;
interfacial condensation
;
phosgene
;
cyclic carbonate
;
chloroformate
;
bisphenol
;
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Maschinenbau
,
Physik
Notizen:
Cyclic oligomeric carbonates are prepared by a hydrolysis/condensation reaction from aromatic bis(chloroformate)s. Three methods for convenient preparation of bis(chloroformate)s have been developed: (1) use of diethylaniline to scavenge HCl, in a modification of an earlier procedure; (2) low pH, low temperature interfacial condensation of bisphenols with phosgene; and (3) use of Ca(OH)2 in interfacial condensation with phosgene. Reaction parameters which control formation of monomeric bis(chloroformate)s versus higher oligomerization include temperature, pH, and rate of phosgene addition. For water-soluble bisphenols such as hydroquinone, the phase ratio of water to CH2Cl2 can also be important.
Zusätzliches Material:
4 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/pi.1995.210370305
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