Although alkyl esters of the aromatic sulfonic acids have long been known as alkylating agents, the real development of these reagents has been more recent and even now they are used only for the unusual alkyla- tion reactions. The alkyl halides and sulfates are the common reagents for introducing alkyl groups and itre unquestionably the most useful re- agents for the lower molecular weight radicals. However, the higher alkyl halides (ten carbons or more) ...
