An efficient improved one-pot synthesis of thiazolo<span style="mso-ansi-language:SV;mso-bidi-font-weight: bold" lang="SV">[2,3-<i style="mso-bidi-font-style:normal">c</i>][1,2,4]triazol-5-yl)-2<i style="mso-bidi-font-style:normal">H</i>-chromen-2-one derivatives <i style="mso-bidi-font-style:normal">via</i> multi-component approach </span>

115-119An efficient improved protocol has been developed for the synthesis of various thiazolo-triazoles via a three-component reaction of various 3-(2-bromoacetyl)-2<i style="mso-bidi-font-style: normal">H-chromen-2-one, thiosemicarbazide and aromatic/aliphatic carboxylic acids using phosphorous oxychloride as the cyclizing agent in toluene at reflux. This method is simple, efficient and requires shorter reaction times in comparison to the multi-step synthesis. The structures of the newly synthesized compounds have been established from analytical and spectral data. </span

One pot synthesis of 4-(arylidene)-2-[5-(4-hydroxy-6-methyl-2-oxo-2<i style="mso-bidi-font-style: normal">H</i>-pyran- 3-yl)-thiazol-2-yl]-5-methyl-2,4-dihydro-pyrazol-3-ones <i style="mso-bidi-font-style: normal">via</i> multi-component approach

1242-1246An efficient, one pot, four-component approach for the synthesis of 4-(arylidene)-2-[5-(4-hydroxy-6-methyl-2-oxo-2<i style="mso-bidi-font-style: normal">H-pyran-3-yl)-thiazol-2-yl]-5-methyl-2,4-dihydropyrazol-3-ones has been described. This synthesis involves the simultaneous formation of thiazole and pyrazole ring systems followed by condensation of different aldehydes on active methylene group of pyrazolone under Knoevenagel reaction conditions. The structures of newly synthesized compounds have been established on the basis of elemental analysis, IR, 1H NMR and mass spectroscopic studies