Hydrogen-bonded chains of rings in 3-tert-butyl-1-phenyl-7-(4-trifluoromethylbenzyl)-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-b]pyridine-5-spiro-1'-cyclohexane-2',6'-dione and 3-tert-butyl-7-(4-methoxybenzyl)-1-phenyl-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-b]pyridine-5-spiro-1'-cyclohexane-2',6'-dione.

Research paper by Jorge J Trilleras, Silvia S Cruz, Justo J Cobo, John N JN Low, Christopher C Glidewell

Indexed on: 06 Dec '08Published on: 06 Dec '08Published in: Acta crystallographica. Section C, Crystal structure communications


In each of 3-tert-butyl-1-phenyl-7-(4-trifluoromethylbenzyl)-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-b]pyridine-5-spiro-1'-cyclohexane-2',6'-dione, C(29)H(30)F(3)N(3)O(2), (I), and 3-tert-butyl-7-(4-methoxybenzyl)-1-phenyl-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-b]pyridine-5-spiro-1'-cyclohexane-2',6'-dione, C(29)H(33)N(3)O(3), (II), the reduced pyridine ring adopts a half-chair conformation. The molecules of compound (I) are linked by two C-H...O hydrogen bonds to form a C(5)C(5)[R(1)(2)(8)] chain of rings, while in compound (II), two C-H...O hydrogen bonds link the molecules into a C(6)C(7)[R(2)(2)(11)] chain of rings, which is further reinforced by a C-H...pi hydrogen bond. The significance of this study lies in its observation of significant differences in hydrogen-bonded structures consequent upon very minor changes in remote substituents.

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