Photochlorination, liquid phase reactions

Instead of the use of sulfuryl chloride, SO2 and CI2, which combine to give sulfuryl chloride, can be employed for vapor-phase reactions. When the ratio of SO2 to CI2 is adjusted, it is feasible to produce sulfonic or chlorosulfonic acid derivatives of saturated paraffins in liquid-phase reactions. According to Lockwood and Richmond, a premixed stream of sulfur dioxide and chlorine can be used for the countercurrent photochlorination of white oil (petroleum fraction, sp gr, 0.8033 bp, 283-324 C) at about 50°C. The product, after hydrolysis with 30 per cent sodium hydroxide, yields an aqueous solution of the sodium salt of a sulfonic or chlorosulfonic acid. An increase in the ratio of SO2 to CI2 greatly increases the yield of solubilized product. When a 3 1 ratio is used, the product contains very little chlorine and has good wetting and detergent characteristics. ... 

Spiropentane (4), which can be considered as a homomethylenecyclopropane, reacted under irradiation with chlorine in the vapor phase to give a mixture of four compounds. Main products were chlorospiropentane (43%) and 4-chloro-2-chloromethylbut-l-ene (36%) together with l,2,4-trichloro-2-chloromethylbutane (16%) and l,l-bis(chloromethyl)cyclopropane (4%) whose proportions were dependent on the irradiation conditions. The latter was formed almost exclusively when the photochlorination reaction was carried out in the liquid phase, but also when the vapor phase chlorination was performed in the dark. ... 

Many types of reactions have mechanisms in this category thermal cracking, some polymerizations, many liquid phase oxidations and combustion reactions, photochlorinations, and others. 

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