Argon-chlorine complexes

Argon - chlorine fluoride (1/1) (weakly bound complex)... 

OxUatiou of primary and secondary alcohals to carbonyl compounds. Corey and Kim report that the complex of N-chlorosuccinimide and dimethyl sulfide is somewhat superior to the complex of dimethyl sulfide and chlorine (this volume) for oxidation of primary and secondary alcohols the formation of hydrogen chloride is avoided and yields are generally higher. The procedure is illustrated for the oxidation of 4-r-butyl-cyclohexanol (2) to 4-r-butylcyclohexanonc (4). The complex (1) is prepared by addition of dimethyl sulfide (4.1 mmole) to a stirred solution of NCS (3.0 mmole) in toluene at 0° under argon. The mixture is cooled to -25° and a solution of 4-r-butylcyclo-hexanol (2.0 mmole, mixture of cis and trans) in toluene is added dropwise. The stirring is continued for 2 hr. at — 25° and then triethylamine (3.0 mmole) in toluene is added dropwise. The ketone (4) is obtained in almost quantitative yield. As in oxidation with the complex of dimethyl sulfide and chlorine, an intermediate sulfoxonium complex (3) is involved. 

When thionyl chloride is heated in an atmosphere of argon with 4-methyl-quinoline for 20 h, the methyl group and the pyridine ring are chlorinated. The mechanism appears to be complex but the product has a fused dithiolone ring. However, treatment of 2-chloro-4-methylquinoline with thionyl chloride does not yield a dithioloquinolinone. 

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