Hydrochloric Acid → Dodecanoyl chloride

Participants

Reaction Steps

To a stirred mass of lauric acid (200 g, 0.999 gmol) and N-lauroyl, N-methyl taurinic lauric mix anhydride (Formula V, RCO=lauroyl, C12) from step I (0.6 g, 0.0012 gmol) at 25° C. under nitrogen blanket, thionyl chloride (123 g, 1.03 gmol) was added slowly at 25° C. and atmospheric pressure over a period of 2 hours maintaining temperature below 25° C. The hydrochloric acid and sulfur dioxide generated during the process was continuously scrubbed in a gas scrubber containing caustic lye. The reaction mixture was stirred for additional 4 hours at the reaction temperature. The progress of reaction in the last phase was monitored by measuring alkanoyl chloride formation. Nitrogen gas was purged through the reaction mass for 3 hours to remove the residual traces of sulfur dioxide, hydrogen chloride gas and unreacted thionyl chloride. At the end of this procedure lauroyl chloride (212 g, 97%) was obtained as practically colorless product. The detailed analysis is given in the Table 3.

Provenance & Evidence