Sulfuric Acid → 1-Octadecanaminium, N,N-dimethyl-N-octadecyl-, sulfate (1:1)

Participants

Reaction Conditions

Reaction Steps

In a 1 liter 3-necked round bottomed flask equipped with a mechanical stirrer and reflux condenser were suspended 60 grams (90.8 millimoles) of distearyl dimethyl ammonium methylsulfate in a mixture of 168.75 grams of methanol and 56.25 grams of deionized water. 9.57 grams of 95 percent sulfuric acid (90.8 millimoles) were then added and the reaction mixture was heated at gentle reflux, at about 71° to 72° C., for 4 hours. The resulting cloudy, emulsion-like mixture was then cooled slowly. After about one hour of slow cooling at about 350° C., droplets formation was observed and at about 300° C. solid particles formation was noticed. The crystallization was continued overnight, about 18 hours, under agitation at about 20° to 25° C. The waxy slurry was filtered under vacuum on an 11 centimeter Whatman #4,filter paper on a Buchner funnel. The filtration time recorded was 20 minutes. The filter cake was reslurried In 225 grams of a 75/25 mixture of methanol and water to remove residual acidity. The mixture of methanol and water was used in order to attempt to avoid the formation of gel experienced when water only is used to wash the highly acidic wet cake. A waxy, semigelatinous slurry was obtained, which required 20 minutes to filter. One additional reslurry washing was accomplished as described above requiring a filtration time of 35 minutes. A final reslurry wash with 225 grams of acetone was accomplished after which the product was recovered by filtration and dried overnight in vacuum at about 50° C. 41.7 grams (71.0 percent yield) of distearyl dimethyl ammonium bisulfate was recovered. Analyticals: melting point (DSC) 93.1° C., H2O content 0.11 percent, bisulfate content (by titration) 14.22 percent (theoretical 14.99 percent), and a different IR fingerprint from the material of COMPARATIVE Example I.

Provenance & Evidence