Chapter 6, Problem 29P

If the temperature is not kept below ${\text{25}}^{\text{o}}\text{C}$ during the reaction of primary alcohols with $\text{p-toluenesulfonylchloride}$ in pyridine, it is sometimes observed that the isolated product is not the desired alkyl $\text{p-toluenesulfonate}$ but is instead the corresponding alkyl chloride. Suggest a mechanistic explanation for this observation.