Gregory J. Withbroe

Design and synthesis of a novel family of triazine-based inhibitors of sorbitol dehydrogenase with oral activity: 1-{4-[3R,5S-dimethyl-4-(4-methyl-[1,3,5]triazin-2-yl)-piperazin-1-yl]-[1,3,5]triazin-2-yl}-(R) ethanol

Two new templates, (R) 2-hydroxyethyl-pyridine and (R) 2-hydroxyethyl-triazine, were used to design novel sorbitol dehydrogenase inhibitors (SDIs). The design concept included spawning of these templates to function as effective ligands to the catalytic zinc within the enzyme through incorporation of optimally substituted piperazino-triazine side chains so as to accommodate the active site in the enzyme for efficient binding. This strategy resulted in orally active SDIs, which penetrate key tissues, for example, sciatic nerve of chronically diabetic rats. The latter template led to the design of the title inhibitor, 33, which normalized the elevated sciatic nerve fructose by 96% at an oral dose of 10mg/kg.

Synthesis of (1‐(Aminomethyl)‐2,3‐dihydro‐1H‐inden‐3‐yl)methanol: Structural Confirmation of the Main Band Impurity Found in Varenicline® Starting Material

Abstract Described here is the synthesis of (1‐(aminomethyl)‐2,3‐dihydro‐1H‐inden‐3‐yl)methanol 1, the previously unidentified impurity found in the synthesis of 2,1 providing a confirmation of the structure. Fabbrica Italiano Sintetici (FIS), working in conjunction with Pfizer Groton, reported an unidentified impurity, referred to as the “main band impurity”, in 2 at levels of 0.4 to 0.8%. The structure was postulated to be 1, the open‐ring product of the lithium aluminum hydride (LAH) reduction of 3 to 2. Although the cis isomer of 1 was previously reported in the literature,2 a much shorter racemic synthesis was developed using intermediates employed for the production of Varenicline®. Several reducing agents were screened for the synthesis of 1, with LiAlH4 followed by basic workup conditions giving optimal results. High performance liquid chromatography (HPLC) analysis ultimately confirmed the structure of 1 as the main band impurity generated during the synthesis of 2.