Refluxing 2-methylpyridine-3-carboxylic acid with thionyl chloride for 6–7 h gave (∼50%) title compound dichlorothienolactone 2 as was confirmed by a X-ray structure analysis. The propylaminolysis of 2 provides a new and convenient access to highly functionalised pyrrolo[3,4-b]pyridine derivatives.
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