Novel 1,2,4-triazolo[3,4-b][1,3,4]thiadiazine bearing substituted phenylquinolin-2-one moiety

Figure 1.

General structure of final synthesized derivatives.

Scheme 1. 

Synthetic Scheme for 1,2,4-triazolo[3,4-b][1,3,4]thiadiazine bearing substituted phenylquinolin-2-one (4a–4t). Where R = H, 2-Br, 3-Br, 4-Br, 2-Cl, 3-Cl, 4-Cl, 2-F, 3-F, 4-F, 2-NO₂, 3-NO₂, 4-NO₂, 2-CH₃, 3-CH₃, 4-CH₃, 2-OCH₃, 3-OCH₃, 4-OCH₃, 3,4,5-t-OCH₃. Reagents and conditions: (a) C₂H₅OH, Nitrobenzene, Con. H₂SO₄, reflux, 80 °C, 4 h; (b) chloroacetic acid, NaHCO₃, water, CuO, reflux, 80 °C, 5 h; (c) thiocarbohydrazide, Δ, 2 h; (d) phenacyl bromide, anhydrous ethanol, NH₄OH, 50 °C, 6 h.

 In the present work twenty derivatives of phenylquinoline-1,2,4-triazolothiadiazines were synthesized. The structures of the synthesized compounds were established by spectral data. According to IR spectroscopic data compounds (4a–4t) showed peaks at 1306–1330 cm⁻¹, 650–682 cm⁻¹ due to -NC and CSC stretching vibrations respectively and no absorption peaks at 3140–3280 cm⁻¹, 3050–3090 cm⁻¹ due to -NH₂ and -SH groups respectively indicated smooth cyclization of triazoles leading to the formation of thiadiazine ring. Further, ¹H NMR spectra of the synthesized compounds were confirmed by the appearance of SCH₂ proton of 1,3,4-thiadiazine ring at 4.40–4.54 ppm and CH₂ proton at 5.97–6.20 ppm as broad singlet. All other aromatic protons were observed at expected region. Mass spectra (ESI-MS) of all the synthesized compounds showed molecular ion [M + H]⁺ peak in agreement with their molecular formula. Physical and elemental analyses are listed in Table 1.

2.6.20. 6,7,8-Trimethoxy-4-phenyl-1-({6-phenyl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl}methyl)-1,2-dihydroquinolin-2-one (4t)

White needle Crystal; IR (KBr, cm⁻¹): 3023 (Ar CH str), 2901 (Aliphatic CH str),1706 (CO str), 1620 (CN str), 1564 (CC str), 1330 (Ar CN str), 683 (CSC); ¹H NMR (CDCl₃, 300 MHz): δ (ppm): 3.84 (s, 9H, 3xOCH₃), 4.51 (s, 2H, SCH₂), 5.98 (s, 2H, CH₂), 6.85 (s, 1H, CH), 7.45(d, 2H, J = 8.5 Hz, ArH), 7.48(m,5H, ArH), 7.74 (q, 4H, ArH). ESI-MS (m/z) calcd. is 539.6, found 540.7 [M + H]⁺; anal. calcd. for C₂₉H₂₅N₅O₄S (539.60): C 64.55, H 4.67, N 12.98; found: C 64.54, H 4.63, N 12.95.

 Arabian Journal of Chemistry
 

Available online 11 July 2015

In Press, Corrected Proof — Note to users

ORIGINAL ARTICLE

Synthesis, characterization and antimicrobial evaluation of some novel 1,2,4-triazolo[3,4-b][1,3,4]thiadiazine bearing substituted phenylquinolin-2-one moiety

• Swagatika Ghosh^a, ,
• Amita Verma^{a, ,} ,
• Alok Mukerjee^b,
• Milan Kumar Mandal^a

• ^a Department of Pharmaceutical Sciences, Faculty of Health Sciences, Allahabad, Uttar Pradesh 211007, India
• ^b Department of Pharmaceutical Chemistry, United Institute of Pharmacy, UPSIDC, Naini, Allahabad, Uttar Pradesh 211010, India

Received 3 April 2014, Accepted 7 July 2015, Available online 11 July 2015

Open Access funded by King Saud University

Under a Creative Commons license

http://www.sciencedirect.com/science/article/pii/S187853521500218X

doi:10.1016/j.arabjc.2015.07.003

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