Synthesis of 1,2,3,4,9,9-hexachloro-1,4,4a,5,6,7,-8,8a-octahydro-1,4-methanonaphthalene-6,7-dicarboxylic acid and ester derivatives

Abstract

S-O. 'Analyzed by Galbraith Laboratories, Knoxville, Tenn. 'Not enough for NMR analysis.analysis by NMR indicated a mixture of 85% 1,2,2,2-tetrachloroethanesulfenyl chloride and 15% of the 1,1,2,2-tetrachloroethyl isomer). Water was then added to the mixture and the light yellow organic product separated. The aliphatic compounds were diluted with ether and dried over sodium sulfate before chromatographing. The aromatic compounds, which did not crystallize from the oil, were handled similarly.The compounds, which were purified by thin-layer chromatography, were applied in about 5% ether solution to plates coated to a thickness of 250 microns with silica gel GF 254 (Merck) containing a fluorescent indicator, and were developed in benzene, or benzene-petroleum ether (30 to 60°C .)-chloroform, 8:8:1 by volume.The NMR data were obtained on a Varían DP-60 nuclear magnetic resonance spectrometer. Chemical shifts were determined by side bands applied with an audio-oscillator for which the frequency is continuously monitored by an electronic counter. The samples were run in a concentration of 20 to 40% by volume in carbon tetrachloride at a temperature of approximately 33°C.The infrared spectra were obtained on a Beckman IR-4 spectrophotometer using sodium chloride optics. The liquid samples were run neat and the solids in Nujol mulls.