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Free keywords:
2-aminothiazole; Hantzsch reaction; heterocycle; solid solution; hydrogen bonding; crystal structure
Abstract:
The synthesis of ethyl 2-[(4-methylpyridin-2-yl)amino)-4-(pyridin-2-yl)thiazole-
5-carboxylate via the Hantzsch reaction and partial in situ transesterification
during recrystallization from methanol-d4 to the d3-methyl ester, resulting in the
title solid solution, ethyl 2-[(4-methylpyridin-2-yl)amino)-4-(pyridin-2-yl)thia-
zole-5-carboxylate–d3-methyl 2-[(4-methylpyridin-2-yl)amino)-4-(pyridin-2-yl)thiazole-5-carboxylate (0.88/0.12), 0.88C17H16N4O2S∙0.12C16D3H11N4O2S, is
reported. The refined ratio of ethyl to d3-methyl ester in the crystal is 0.880 (6):0.120 (6). The pyridine ring is significantly twisted out of the plane of
the approximately planar picoline thiazole ester moiety. N—H∙ ∙ ∙N hydrogen
bonds between the secondary amino group and the pyridine nitrogen atom of an
adjacent symmetry-related molecule link the molecules into polymeric hydrogen-bonded zigzag tapes extending by glide symmetry in the [001] direction. There is structural evidence for intramolecular N∙ ∙ ∙S chalcogen bonding and intermolecular weak C—H∙ ∙ ∙O hydrogen bonds between adjacent zigzag tapes.
