Diethyl 2,6-dimethyl-4-p-tolyl-1,4-dihydropyridine-3,5-dicarboxylate

Abstract

Key indicators: single-crystal X-ray study; T = 100 K; mean (C-C) = 0.002 Å; R factor = 0.057; wR factor = 0.147; data-to-parameter ratio = 23.0.In the title compound, C 20 H 25 NO 4 , the 1,4-dihydropyridine ring adopts a flattened-boat conformation and forms a dihedral angle of 89.77 (8) with the benzene ring. Intermolecular N-HÁ Á ÁO hydrogen bonds result in the formation of extended chains parallel to the b axis. Related literature

Dimethyl 4-(4-hydroxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate

“…The methyl groups are nearly coplanar with the aformentioned plane of the atoms C8/C9/C10/C11, with the methyl C atoms C12 and C13 deviating from the mean plane by 0.12 (4) and 0.22 2Å, respectively. The average C-N bond lengths of the title compound are with 1.353 (9) Å similar to those of its phenyl substituted 1,4-dihydropyridine derivative (Bai et al, 2009) which has average C-N bond lenghts of 1.376 (8) Å, its 4methoxyphenyl substituted 1,4-dihydropyridine derivative (Thenmozhi et al, 2009) which has average C-N bond lenghts of 1.377 (4) Å, and its 4-methylphenyl substituted 1,4-dihydropyridine derivative (Fun et al, 2009) which has average C-N bond lenghts of 1.385 (7) Å.…”

“…For background to the bioactivity and synthesis of 1,4dihydropyridines, see: Yang et al (2010); Davies et al (2005); Warrior et al (2005); Ko & Yao (2006); Rose & Draeger (1992). For related structures, see: Bai et al (2009); Fun et al (2009); Thenmozhi et al (2009). For hydrogen-bond definitions, see: Desiraju & Steiner (1999).…”

Ionic Liquid [EMIM]OAc under Ultrasonic Irradiation towards Synthesis of 1,4‐DHP's

“…19,22,23 During the last three decades, in organic synthesis ultrasound irradiation 24 has been considered as a clean, convenient and useful protocol compared with traditional methods and hence, a large number of organic reactions can be carried out with higher yields in shorter reaction time under mild conditions. [25][26][27][28] In continuation of our earlier interest in 1,4-DHP's [29][30][31][32][33][34][35] as well as considering its significance herein we report an efficient and simple procedure for preparation of 1,4-DHP's at room temperature under ultrasonication using ionic liquid [EMIM]OAc as catalyst (see Scheme I). Table 1.…”