Sulfur trioxide, addition compounds with pyridine, dimethylaniline

See also Sulfuryl chloride) Sulfur trioxide, addition compounds with pyridine, dimethylaniline, and dioxane, 2 173, 174 for synthesis of deuterosulfuric acid, 6 121... 

The use of sulfur trioxide as a sulfonating agent is often inconvenient, and reactions carried out with it are usually vigorous and difficult to control. The addition compounds-that sulfur trioxide forms with tertiary amines and other strong electron donors, however, have been found to be very convenient sulfonating agents. Procedures for the preparation of three typical compounds, pyridine-sulfur trioxide, CsHsN-SOa dimethylaniline-sulfur trioxide, CeHs-N(CH3)2 SOs and dioxane-sulfur trioxide, 0(CH2 CH2)20 -SO3, are presented here. 

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