Microwave Assisted Synthesis and Anti-HIV-RT Activity of Diaryl Benzo[1,3]thiazin-4-ones

Abstract

A series of novel diaryl benzothiazin-4-ones were designed and synthesized by the three-component one-pot cyclocondensation of pyrimidinamine, aromatic aldehyde and thiosalicylic acid under microwave irradiation for 10 min. The reaction has the advantages such as short reaction time and simple operation. The structures of the newly synthesized compounds were confirmed by IR, NMR, MS spectra and elemental analysis. The compound 2-(2,6-dichlorophenyl)-3-(4,6-dimethylpyrimidin-2-yl)-2H-benzo[e][1,3]thiazin-4(3H)-one (10c) could effectively inhibit HIV-RT activity with the IC 50 value of 8.38 µmol•L-1 , the others showed middle RT inhibitory activity.

Synthesis and spectroscopic properties of a series of novel 2-aryl-3-phenyl-2,3-dihydro-4H-1,3-benzothiazin-4-ones

“…19 Updated procedure: after chromatography on 30 g silica gel with mixtures of EtOAc and hexanes, recrystallization from EtOH gave off-white crystals 0.67 g (30%). 1 2-(3-Nitrophenyl)-3-phenyl-2,3-dihydro-4H-1,3-benzothiazin-4-one (1c). 17 Melting point and Rf previously reported.…”

“…Rf (30% EtOAc/hexanes): 0.54. 1 2-(3-Methylphenyl)-3-phenyl-2,3-dihydro-4H-1,3-benzothiazin-4-one (1l). The imine was used as a crude liquid.…”

“…7 More narrowly, N-aryl (R 1 = aryl or heteroaryl) compounds in this family have shown antitumor, 3,5,8 cyclooxygenase COX-2 enzyme inhibition, 9 HIV-RT inhibition, 1 and antimicrobial activity. 10 Although this structure is not yet considered to be a privileged scaffold,…”

Crystal structure of 2,3-diphenyl-2,3-dihydro-4H-1,3-benzothiazin-4-one 1-oxide

“…The 2,3-dihydro-4H-1,3-benzothiazin-4-one scaffold has shown a wide range of bioactivity, including antitumor (Li et al, 2012;Wang et al, 2015;Kamel et al, 2010;Nofal et al, 2014), antimicrobial (Popiolek et al, 2016;Mandour et al, 2007), antimalarial (Mei et al, 2013), HIV-RT inhibition (Jeng et al, 2015;Hou et al, 2016) and cyclooxygenase COX-2 enzyme inhibition (Zarghi et al, 2009). The S-oxides of these compounds have been little studied (a search found fewer than 50), despite the evidence of enhanced activity in the similar 2,3,5,6-tetrahydro-4H-1,3-thiazin-4-ones (Surrey et al, 1958;Surrey, 1963a,b) and 1,3-thiazolidin-4-ones (Gududuru et al, 2004).…”

T3P‐promoted synthesis of a series of novel 3‐aryl‐2‐phenyl‐2,3‐dihydro‐4H‐1,3‐benzothiazin‐4‐ones

“…The 2,3-dihydro-4H-1,3-benzothiazin-4-ones (Figure 1) are a class of compounds that have demonstrated a variety of types of bioactivity. [1][2][3][4][5][6][7][8][9][10] This may be a function of both the 1,3-thiazin-4-one ring [11] and the fused benzene. [12] An assortment of methods have been reported for the preparation of 2,3-dihydro-4H-1,3-benzothiazin-4-ones.…”