Structure of (R,R)-4-bromo-2-{4-[4-bromo-1-(4-toluenesulfonyl)-1H-pyrrol-2-yl]-1,3-dinitrobutan-2-yl}-1-(4-toluenesulfonyl)-1H-pyrrole, another ostensible by-product in the synthesis of geminal-dimethyl hydrodipyrrins

Abstract

The crystal structure of (R,R)-4-bromo-2-{4-[4-bromo-1-(4-toluenesulfonyl)-1H-pyrrol-2-yl]-1,3-dinitrobutan-2-yl}-1-(4-toluenesulfonyl)-1H-pyrrole (1, C26H24Br2N4O8S2) is presented. The title compound was isolated in suitable yield as a by-product in our synthesis of geminal-dimethyl hydrodipyrrins. We observe an unforeseen enantiomeric resolution both in the bulk sample and the crystal of 1, with distinct C—H...O (Cmethyl—H...Onitro, Csp 3—H...Osulfonyl) interactions observed in the enantiomers present, along with other interactions, namely C5-pyrrolyl—H...Osulfonyl, forming a polymer along the crystallographic c-axis direction. Whilst pyrrolic fragments are well documented in the literature, little data is found surrounding the 1,3-dinitrobutane scaffold.