ABSTRACT
Various poly(alkylene sulfide)s have been synthesized and used as catalysts to enhance the para-regioselectivity in chlorination of phenol and 2-chlorophenol using freshly distilled sulfuryl chloride in the presence of AlCl3 as an activator. Poly(alkylene sulfide)s having alternating spacers, one having three methylene groups and the second having three, six or nine methylene groups were the most para-regioselective catalysts in chlorination of both phenol and 2-chlorophenol. For example, chlorination of phenol and 2-chlorophenol in the presence of optimal examples of such poly(alkylene sulfide)s gave 4-chlorophenol and 2,4-dichlorophenol as the major products in 94.8 and 95.4% yields, respectively, compared with 75.4 and 55.0% yields in the absence of catalysts. In addition, double chlorination of phenol in the presence of poly(alkylene sulfide)s gave 2,4-dichlrophenol in up to 97.1% yield compared with only 58.6% in the absence of catalysts.
GRAPHICAL ABSTRACT
![](/cms/asset/317a50ee-17ea-4a59-b32a-6c94d480bccb/gsrp_a_1688815_uf0001_oc.jpg)
Acknowledgements
A. S. Hegazy thanks Swansea and Cardiff Universities for financial support. G. A. El-Hiti is grateful to the Deanship of Scientific Research, King Saud University for funding through Vice Deanship of Scientific Research Chairs.
Disclosure statement
No potential conflict of interest was reported by the authors.
ORCID
Keith Smith http://orcid.org/0000-0003-4838-5651
Gamal A. El-Hiti http://orcid.org/0000-0001-6675-3126