Addition Compound of Sulfur Dioxide and Trimethylamine

Submitted by J. Russell Bbight and W. Conard Fbrnblius Checked by Ralph Firminhac and Roy E. Heath  

Trimethylamine. Aqueous trimethylamine (usually supplied as the 25 per cent solution) is treated (Fig. 18) with solid sodium hydroxide in a flask A connected to a reflux 

II Present address, Wyandotte Chemicals Corporation, Wyandotte, Mich. 

Sulfur Dioxide. The gas, which may be conveniently obtained from a small commercial tank, is passed through concentrated sulfuric acid, then is passed over phosphorus (V) oxide, and finally is condensed in glass ampoules (ice-salt or Dry Ice-acetone bath), where it is stored until used. 

Four hundred milliliters of petroleum ether (dried-over sodium) is poured into a dry three-necked flask fitted with an inlet tube, a mechanical stirrer, and a barium oxide drying tube. The flask is cooled by an ice-salt mixture. Then 46 g. of gaseous amine is slowly added. Next 50 g. of dry sulfur dioxide is added, with continuous stirring and at such a rate that the temperature of the reaction mixture remains at about 0°. The solid sulfur dioxide addition compound is filtered quickly in a Buchner funnel. The product is then left in vacuo over phosphorus (V) oxide for several hours. Yield 90 to 96 g. (94 to 100 per cent). Anal. Calcd. for (CH3)3 N SO2 N, 11.4. Found N, 11.4 11.5. 

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