Reactions of pentachlororesorcinol with chlorinating agents: Identification of the products

CHED 1136

Ashley Marie Ramirez, aramirez@ptloma.edu1, Matthew D. Alexander, malexand@ucsd.edu2, Peter E Baker1, Ryan H. DeBoard1, Dennis C. Madrid, dmadrid@ixpres.com1, Victor Heasley, vheasley@ptloma.edu1, Jeffrey L. Boerneke, jboernek@pointloma.edu1, and Torie L. Hartge1. (1) Department of Chemistry, Point Loma Nazarene University, 3900 Lomaland Drive, San Diego, CA 92106, (2) Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Dr, La Jolla, CA 92093-0358
Resorcinol (1) is a model compound of the humic acids, whose reaction with chlorinating agents (such as NH2Cl) is used for the treatment of drinking water. The reactions of 1 with both NH2Cl and NaOCl have been thoroughly investigated for the production of CHCl3, but other potential products have not been investigated. It has been known for some time that chlorination of 1 leads to the production of a pentachlorinated derivative, 2,2,4,4,6-pentachloro-5-cyclohexen-1,3-dione (2), whose reaction with chlorinating agents has not been investigated in detail. It was this limited research that spurred our interest in the reaction of 2 with chlorinating agents and accompanying reagents including NH3, NH2Cl, SOCl2, and NaOCl. Our poster will report on the modified, simpler procedure for the synthesis of 2, and the synthesis of four main products from 2: (5z)-4-chloro-5-(chloromethylene)-1,5-dihydro-2H-pyrrol-2-one (3), 4-chloro-5-(dichloromethylene)-1,5-dihydro-2H-pyrrol-2-one (4), (2E)-3,5,5,5-tetrachloro-4-oxopent-2-enoyl chloride, and (2E)-3,5,5,5-tetrachloro-4-oxopent-2-enoic acid (5). The structures of these products have been confirmed by their mass spectra (GC-MS), a combination of 1H, 13C NMR and IR spectra (GC-FTIR), exact mass determinations, elemental analysis, and x-ray crystallography data.