X-ray crystallography of methyl (6-amino-5-cyano-2-methyl-4-(2-nitrophenyl)-4 H -pyran)-3-carboxylate

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TRUCTURE OF ORGANIC COMPOUNDS

X-ray Crystallography of Methyl (6-amino-5-cyano-2-methyl-4-(2-nitrophenyl)-4H-pyran)-3-carboxylate1 Suresh Sharmaa, Bubun Banerjeeb, Goutam Brahmacharib, Rajni Kanta, and Vivek K. Guptaa,* a

X-ray Crystallography Laboratory, Post-Graduate Department of Physics and Electronics, University of Jammu, Jammu Tawi-180 006, India b Laboratory of Natural Products and Organic Synthesis, Department of Chemistry, Visva-Bharati (a Central University), Santiniketan 731 235, West Bengal, India *e-mail: [email protected] Received February 16, 2016

Abstract—The organic carbonitrile namely methyl (6-amino-5-cyano-2-methyl-4-(2-nitrophenyl)-4Hpyran)-3-carboxylate is synthesized via one-pot multi-component reaction at room temperature using commercially available urea as inexpensive and environmentally benign organo-catalyst and its crystal structure is determined by X-ray technique. The crystals are monoclinic, sp. gr. C2/c, a = 12.3069(8) Å, b = 9.7023(7) Å, c = 24.812(2) Å, β = 94.862(6)°, Z = 8. The dihedral angle between pyran and phenyl rings is 87.8(1)°; the pyran ring is almost planar The dihedral angle between the mean planes of phenyl ring and nitro group is 44.4(2)°. The crystal structure is stabilized by N−H···N and N−H···O hydrogen bonds. In addition, C−H···π interactions are also observed in the crystal structure. DOI: 10.1134/S1063774516070105

INTRODUCTION 4H-Pyrans represent a “privileged” structural motif well distributed in naturally occurring heterocyclic compounds [1–3] with a broad spectrum of significant biological activities including anticancer [4], cytotoxic [5], anti-HIV [6–8], anti-inflammatory [9], anti-malarial [10], and antimicrobial [11] activities. Recently, a series of synthetic 2-amino-3-cyano-4Hpyrans have been found to possess potent anticancer, antibacterial, antifungal, and anti-rheumatic properties. In this communication, we report the structure of a 4H-pyran derivative, namely methyl 6-amino-5cyano-2-methyl-4-(2-nitrophenyl)-4H-pyran)-3-carboxylate (I) which is synthesized via one-pot multicomponent reaction at room temperature using commercially available urea as inexpensive and environmentally benign organo-catalyst.

acetoacetate (0.116 g, 1 mmol) was added to the stirred reaction mixture, and the stirring was continued for 11 h [12]. The progress of the reaction was monitored by TLC. On completion of the reaction, a solid mass precipitated out that was filtered off followed by washing with aqueous ethanol. Crude product was purified by recrystallization from ethanol without carrying out column chromatography. Single crystal was obtained from DMSO. For crystallization, 50 mg of compound was dissolved in 5 mL DMSO and left at ambient temperature. After several days, white block shaped crystals were obtained. The chemical diagram of the title compound is shown in Fig. 1. Characterization. Yellow solid. 0.271 g, yield 86%, m. p. 473−475 K. IR (KBr) νmax/cm−1: 3450, 3317, 3204, 3015, 2941, 2199, 1676, 1595, 1518, 1416, 1358, 1234, 1175, 1124, 1063, 951,