Molecular and Crystal Structures of Bispidine Conjugates and Tempo Radicals

Abstract

Molecular and crystal structures of the following bispidine conjugates with stable TEMPO radicals and their synthetic precursors are described for the first time: 4-(2-bromacetoamido)-2,2,6,6-tetramethylpiperidine-1-oxyl (2), tert-butyl-3,7-diazabicyclo[3.3.1]nonan-3-carboxylate (4), 2-(1-oxyl-2,2,6,6-tetramethylpiperidine-4-yl)acetamide (3,7-diazabicyclo[3.3.1]nonan-3-carboxylate (6) and 2,2′-(1,5-dimethyl-3,7-diazabicyclo[3.3.1]nonan-3,7-diyl)bis[N-(2,2,6,6-tetramethyl-1-oxyl-piperidine-4-yl)acetamide] (7). These conjugates are prepared by the alkylation of bispidines using TEMPO bromo-derivatives.