Pentane 1,1,1,5-tetrachloro

Pentane 1.3-Dibromo-2,5.5.5-tetrachloro-1.1.2-Lrtflaoro-EI0b2, 133/1 35 (Educt)... 

Caution. Diazo compounds are potentially explosive. Although neat 5-diazo-l,3-cyclopentadiene is known to be highly explosive,6 it may be handled conveniently and safely in a pentane solution.2,1 Tetrachloro-5-diazo-l,3-cyclopentadiene is reported to be stable, but due caution should be exercised in the manipulation of this compound. Carbon monoxide, volatile metal carbonyls, and some diazo compounds are highly toxic, and reactions with these species should be conducted in a well-ventilated fume hood. Avoid inhalation or contact with skin. 

Chromium metal (26.0 g, 0.50 mol) was dissolved in 4M HCl (240 mL, 0.96 mol) under a Nj atmosphere to give a blue solution of CrClj. After 4 h, when evolution of H2 had ceased and most of the metal had dissolved, a solution of l,5,6,7-tetrachloro-8,8-dimethoxy-c rfo-tricyclo[3.2.1.0 ]oct-6-ene (12.16g, 0.040 mol) and ethylenediamine (120 g, 2.0 mol) in DMF (800 mL) was added dropwise and the mixture was stirred magnetically for 36 h under Nj. The maroon-colored mixture was then poured into HjO and the product extracted into EtjO (3 x lOOmL). The combined EtjO extracts were washed thoroughly with HjO, dried, and evaporated to give a clear oil, which solidified when cooled to — 10°C. The solid was crystallized from pentane (at — 20°C) to give the product as chunky white crystals mp 22.5-23.5°C. 

Exxsol Isopentane S. See n-Pentane Exxsol Methylpentane Naphtha. See Hexane Exxsol Pentane 80. See n-Pentane Eypel F. See Polyfluoroalkoxyphosphazene EZA . See Sodium silicoaluminate E-Z Cadox. See Cadmium oxide E-Z Flow CA] E-Z Flow MT] E-Z Flow PT] E-Z FlowVT. See Talc F11. SeeTrichlorofluoromethane F 12. SeeDichlorodifluoromethane F 13B1. See Trifluorobromomethane F-20 Feldspar. See Feldspar F21. SeeDichlorofluoromethane F 22. See Chlorodifluoromethane F 112. See 1,1,2,2-Tetrachloro-1,2-difluoroethane... 

Though inert towards chlorine at room temperature in the dark, perfluoropenta-1,2-diene is rapidly converted into the saturated tetrachloride, 1,2,2,3-tetrachloro-octafluom-n-pentane (95 %), and a small amount of mixed dimers, (CjFjIj (4%), when photolysed in the presence of an excess of chlorine. Photochemical hydrobromination yields mainly 3/f-2-bromo-octafluoropent-1-ene (34) and 1 W-2-bromo-octafluoropent-2-ene (35), a result which indicates that bromine atom preferentially attacks the central carbon of the allenic system to give an intermediate radical (36) which exists long enough to permit 90° rotation of the orbital containing the unpaired electron, so that it is transformed into an allylic radical (37) (see Scheme 14). 

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