Pentane photochemical chlorination

Photochemical chlorination of pentane gave a mixture of three isomenc monochlorides The pnncipal monochlonde constituted 46% of the total and the remaining 54% was approximately a 1 1 mixture of the other two isomers Write structural formulas for the three monochlonde iso mers and specify which one was formed in greatest amount (Recall that a secondary hydrogen is abstracted three times faster by a chlonne atom than a pnmary hydrogen)... 

Photochemical chlorination of pentane gave a mixture of three isomeric monochlorides. 

Methane, chlorine, and recycled chloromethanes are fed to a tubular reactor at a reactor temperature of 490—530°C to yield all four chlorinated methane derivatives (14). Similarly, chlorination of ethane produces ethyl chloride and higher chlorinated ethanes. The process is employed commercially to produce l,l,l-trichloroethane. l,l,l-Trichloroethane is also produced via chlorination of 1,1-dichloroethane with l,l,2-trichloroethane as a coproduct (15). Hexachlorocyclopentadiene is formed by a complex series of chlorination, cyclization, and dechlorination reactions. First, substitutive chlorination of pentanes is carried out by either photochemical or thermal methods to give a product with 6—7 atoms of chlorine per mole of pentane. The polychloropentane product mixed with excess chlorine is then passed through a porous bed of Fuller s earth or silica at 350—500°C to give hexachlorocyclopentadiene. Cyclopentadiene is another possible feedstock for the production of hexachlorocyclopentadiene. 

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). 

---