2,3,5,6-Tetrachloro

On reaction of methyl trifluoropyruvate with phosphorus pentachlonde 1,1,2,2 tetrachloro-3,3,3-trifluoro-l-methoxypropane IS obtained [273] Hexafluo-roacetone hydrazone is oxidized to bis(tnfluoromethyl)diazomethane upon tieat-ment with phosphorus pentachlonde [274]... 

A ceramic fiber with Si-C-N-0 composition can be prepared by melt-spinning, cure and pyrolysis of a polymethyldisilylazane polymer precursor (14, 15), which is the reaction product of a mixture of 50 mol % 1,1,2,2- tetrachloro-1,2-dimethyldisilane (la), 40 mol % 1,1,2-trichloro- 1,2,2-trimethyldisilane (lb) and 10 mol %... 

Acetylcyclopentane-l,3-dione has been obtained in small amounts from the aluminum chloride-catalyzed reactions of vinyl acetate and succinyl chloride in 1,1,2,2-tetrachloro-ethane. 2-Acetylcyclopentane-l,3-diones have been prepared via Dieckmann condensation of 1,4-bisethoxycarbonylhexane-3,5-diones. The present procedure is essentially that of Mer nyi and Nilsson with some modifications. 

Toxicology. At high concentrations, 1,1,2,2-tetrachloro-l,2-difluoroethane affects the nervous system and causes pulmonary edema in animals it is expected that severe exposure in humans will produce the same effects. 

Tetrachloro-1,2 -difluoroethane was mildly irritating to rabbit eyes and guinea pig skin. 

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