Ethyl 2-amino-4-(4-methyl-1,3-thia­zol-5-yl)-5-oxo-4H,5H-pyrano[3,2-c]chromene-3-carboxyl­ate

V Karthikeyan; V Ramkumar; R Joel Karunakaran

doi:10.1107/S1600536813021703

. 2013 Aug 10;69(Pt 9):o1411–o1412. doi: 10.1107/S1600536813021703

Ethyl 2-amino-4-(4-methyl-1,3-thiazol-5-yl)-5-oxo-4H,5H-pyrano[3,2-c]chromene-3-carboxylate

V Karthikeyan ^a, V Ramkumar ^b, R Joel Karunakaran ^a,^*

PMCID: PMC3884413 PMID: 24427048

Abstract

There are two independent molecules in the asymmetric unit of the title compound, C₁₉H₁₆N₂O₅S, in which the thiazole rings make dihedral angles of 80.89 (11) and 84.81 (11)° with the pyrano[3,2-c]chromene ring systems. An intramolecular N—H⋯O hydrogen bond involving the amino group occurs in each independent molecule. In the crystal, the amino groups are involved in N—H⋯O and N—H⋯N hydrogen bonds.

Related literature

Similar conformations were observed in the structures of ethyl 2-amino-5-oxo-4-(p-tolyl)-4H,5H-pyrano[3,2-c]chromene-8-carboxylate (Wang et al., 2004 ▶) and ethyl 2-amino-4-(2,4-dichlorophenyl)-4H-benzo[f]chromene-3-carboxylate (Shi et al., 2003 ▶). For applications of 4H-chromene and its derivatives, see: Jeso & Nicolaou (2009 ▶); Alvey et al. (2008 ▶, 2009 ▶); Bedair et al. (2001 ▶); El-Agrody et al. (2002 ▶, 2011 ▶); Abd-El-Aziz et al. (2004 ▶); Sabry et al. (2011 ▶).

Experimental

Crystal data

C₁₉H₁₆N₂O₅S
M _r = 384.41
Monoclinic,
a = 15.6232 (10) Å
b = 15.0696 (9) Å
c = 15.9063 (11) Å
β = 98.873 (2)°
V = 3700.1 (4) Å³
Z = 8
Mo Kα radiation
μ = 0.21 mm⁻¹
T = 298 K
0.35 × 0.25 × 0.15 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.931, T _max = 0.970
18921 measured reflections
6130 independent reflections
3527 reflections with I > 2σ(I)
R _int = 0.042

Refinement

R[F ² > 2σ(F ²)] = 0.048
wR(F ²) = 0.145
S = 1.03
6130 reflections
491 parameters
H-atom parameters constrained
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.29 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT-Plus (Bruker, 2004 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536813021703/bx2447sup1.cif

e-69-o1411-sup1.cif^{(667.2KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813021703/bx2447Isup2.hkl

e-69-o1411-Isup2.hkl^{(336KB, hkl)}

Click here for additional data file.^{(6.9KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813021703/bx2447Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1B⋯O4	0.86	2.11	2.698 (3)	125
N1—H1B⋯N2A ⁱ	0.86	2.49	3.152 (3)	135
N1—H1C⋯N2ⁱⁱ	0.86	2.27	3.116 (4)	167
N1A—H1A2⋯N2A ⁱⁱⁱ	0.86	2.13	2.988 (4)	174
N1A—H1A1⋯O4A	0.86	2.09	2.690 (3)	126
N1A—H1A1⋯O4ⁱⁱ	0.86	2.52	2.936 (3)	111

Open in a new tab

Symmetry codes: (i) Inline graphic ; (ii) ; (iii) .

Acknowledgments

The authors acknowledge the Department of Chemistry, IIT Madras, for the data collection and Orchid Chemicals and Pharmaceuticals, Chennai, India for providing necessary laboratory facilities.

supplementary crystallographic information

1. Comment

Thiazoles are important class of heterocyclic compounds, found in many potent biologically active molecules such as Sulfathiazol (antimicrobial drug), Ritonavir (antiretroviral drug) and Tiazofurin (antineoplastic drug) similarly 4-Hydroxycoumarin forms the nucleus of many natural products and drugs and is also a key intermediate for the widely used oral anticoagulants and rodenticides. There is interest in fused pyranochromenes because chromene derivatives (Jeso & Nicolaou, 2009; Alvey et al., 2008, 2009); can be used as immunomodulators and for the treatment of different diseases of connective tissues, diabetes, anti-cancer and for applications of 4H-chromene and its derivatives, (Bedair et al. (2001); El-Agrody et al. (2002, 2011); Abd-El-Aziz et al. (2004); Sabry et al. (2011)). We present here the synthesis and crystal structure of the title compound,(I). The molecule is being assessed for biological activity. In the title compound,C₁₉H₁₆N₂O₅, there are two independent molecules in the asymmetric unit. The thiazole rings make a dihedral angle with 4H, 5H-pyrano[3,2-c]chromene ring system of 80.89 (11) and 84.81 (11)°. In the crystal structure, the amino groups are involved in both intra-and intermolecular N—H···O and N—H···N hydrogen bonds respectively, table1.

2. Experimental

A solution of heteroaromatic aldehyde (1 mmol), 1.2 mmol of alkylnitriles, 4-Hydroxy coumarins(1.1 mmol) and catalytic amount of silver trifluoromethanesulfonate (5 mol %) in 10 mL of ethanol and the reaction mixture refluxed for two hours. After completion of the reaction, which was monitored by TLC, the reaction mixture was cooled to room temperature and kept overnight in a refrigerator. The solid mass separated out was filtered and purified by column chromatography using n-Hexane: Ethylacetate mixture in the ratio (3:2). The crude product formed was recrystallized in ethanol.