Reaction Safety:  A Critical Parameter in the Development of a Scaleable Synthesis of 2,3-Bis-chloromethylpyridine Hydrochloride

Autor: Grimm, J. S., Maryanoff, C. A., Patel, M., Palmer, D. C., Sorgi, K. L., Stefanick, S., Webster, R. R. H., Zhang, X.
Zdroj: Organic Process Research & Development; November 2002, Vol. 6 Issue: 6 p938-942, 5p
Abstrakt: This report describes the development of a scaleable process to prepare 2,3-bis(chloromethyl)pyridine hydrochloride, 2, that is safe, economical, and environmentally acceptable. On a small scale this material is prepared using thionyl chloride as the solvent. However, this reaction is not readily scaleable because of environmental and disposal issues. Reaction calorimetry is used to evaluate a number of potentially viable chlorination procedures. In the course of this investigation potentially hazardous reagent/solvent incompatibilities were identified. The use of thionyl chloride in MTBE is particularly hazardous owing to solvent decomposition in the presence of HCl and subsequent outgassing of large amounts of isobutylene. Reaction conditions employing thionyl chloride and 1% v/v DMF in toluene were found to be safe for scale-up. As a result, an environmentally acceptable, safe process has been developed and scaled to produce multikilogram amounts of material.
Databáze: Supplemental Index