Ecofriendly bromination of chalcones and synthesis of flavones using grinding technique

141-145<span style="mso-bidi-font-weight: bold" lang="EN-GB">Selective bromination of chalcones and 2'-hydroxychalcones has been carried out with ammonium bromide and ammonium persulphate using grinding technique at RT under aqueous moist condition to give α,β-dibromochalcones and α,β-dibromo-2'-hydroxychalcones respectively. α,β-Dibromo-2'-hydroxychal­c­ones have been cyclodehydrobrominated with barium hydroxide moist and ethanol at RT to give flavones using grinding technique. <span style="mso-bidi-font-weight: bold"> </span

Molecular iodine mediated one step synthesis and antibacterial properties of some 3-aryl-6-(6-substituted-4-methylcinnolin-3-yl)-<i style="mso-bidi-font-style: normal">7H</i>-1,2,4-triazolo[3,4-<i style="mso-bidi-font-style:normal">b</i>][1,3,4]thiadiazines

313-3173-Aryl-6-(6-substituted-4-methylcinnolin-3-yl)-7H-1,2,4-tria­zolo[3,4-b][1,3,4]thiadiazines 3a-l have been synthesized directly in one step by iodine mediated condensation of 3-acetyl-6-substituted-4-methylcinnoline 1 with 3-aryl-4-amino-5-mercapto-1,2,4-triazoles <b style="mso-bidi-font-weight: normal">2. These compounds have been found to possess very good antibacterial activity at 10 ppm

Microwave assisted synthesis and antimicrobial activity of some 2-(benzo­- furan-2-yl) -7-(substituted)imidazo[2,1-<i style="">b</i>]benzothiazoles

1614-16172-(Benzofuran-2-yl)-7-(substituted)imidazo[2,1-b]benzothia­z­oles have been prepared by condensation of 2-(2-bromoacetyl)­benzofurans and various 2-amino-7-(substituted) benzothiazoles under normal thermal condition as well as microwave irradiations. The latter condition for the reaction has been found to be much more efficient in terms of time and yield. The structures of the compounds have been established on the basis of their elemental analysis, IR and 1H NMR spectral data. The antibacterial and antifungal properties of these compounds are described

An efficient synthesis of 3-bromoflavones under solvent free conditions using grinding technique

770-773Selective bromination of 1-(2-hydroxyphenyl)-3-phenylpro­pane-1,3-diones has been carried out with ammonium bromide and ammonium persulphate at room temperature using grinding technique under solvent free conditions to give 2-bromo derivatives which on cyclodehydration with p-toluenesulphonic acid under grinding conditions give 3-bromoflavones. Also, flavones on bromination using above mentioned conditions give 3-bromoflavones directly

Synthesis and antibacterial properties of some novel 2-substituted-6-(4-methyl-6-substitutedcinnoline-3-yl)imidazo[2,1-<i style="">b</i>][1,3,4]thiadiazoles

1547-1551A series of 2-substituted-6-(4-methyl-6-substitutedcinnoline-3-yl)imidazo[2,1-b][1,3,4] thiadiazoles 5a-k have been synthe­sized by reacting 3-(2-bromoacetyl)-4-methyl-6-substitutedcin­nolines 3 with various 2-amino-5-substituted-1,3,4-thiadiazoles 4 taking absolute ethanol as solvent. The structures of the newly synthesized compounds have been characterized by elemental analysis, IR and 1H NMR spectral data. All the newly synthesized compounds have been tested for their antibacterial properties against gram-positive and gram-negative bacteria

Microwave assisted synthesis and antibacterial properties of some new 2-alkyl/aryl-(6-substitutedcoumarin-3-yl)imidazo[2,1-<i style="mso-bidi-font-style: normal">b</i>][1,3,4]thiadiazoles

291-296A series of 2-alkyl/aryl-(6-substitutedcoumarin-3-yl)imidazo[2,1-<i style="mso-bidi-font-style: normal">b][1,3,4] thiadiazoles 3a-o have been synthesized by reacting 3-(2-bromoacetyl)-6-substitutedcoumarins 1 with various 5-alkyl/aryl-2-amino-1,3,4-thiadiazoles 2 under normal thermal condition as well as microwave irradiation. The latter condition is found to be much more efficient in terms of time and yield. The structures of the newly synthesized compounds have been characterized by elemental analysis, IR and 1H NMR spectral data. All the newly synthesized compounds have been tested for their antibacterial properties against gram-positive and gram-negative bacteria

Synthesis of 2-aryl-5-(benzofuran-2-yl)-thiazolo[3,2-<i style="">b</i>][1,2,4]triazoles using green procedures and their antibacterial activity

531-5363-Aryl-5-(benzofuran-2-yl)acylthio-1,2,4-triazoles 1a-h have been prepared by condensation of 2-(2-bromoacetyl)benzofurans and various 3-aryl-5-mercapto-1,2,4-triazoles under thermal conditions as well as using microwave irradiations and grinding technique. 3-Aryl-5-(benzofuran-2-yl)acylthio-1,2,4-triazoles on cyclisation using polyphosphoric acid under microwave irradia­tions give 2-aryl-5-(benzofuran-2-yl)-thiazolo[3,2-b][1,2,4]tria­zoles 2a-h. Preparation of compounds 1a-h using grinding technique and then cyclisation to 2a-h are in accordance to green procedures as these avoid use of hazardous organic solvents during the reaction as well as at its work-up stage. The antibacterial activity of these compounds has been described

Synthesis of 2-(2-phenylethyl)chromones

535-5362-(2-Phenylethyl)chromones have been obtained by selective reduction of double bond of the styryl group in 2-styryl­chromones involving catalytic hydrogen transfer reaction using ammonium formate in the presence of Pd-C

A green synthesis and antibacterial activity of 2-aryl-5-(coumarin-3-yl)-thiazolo [3,2-b][1,2,4]triazoles

1511-15163-Aryl-5-(coumarin-3-yl)acylthio-1,2,4-triazoles 1a-h have been prepared by direct condensation of 3-acetylcoumarins and various 3-aryl-5-mercapto-1,2,4-triazoles in the presence of molecular iodine using grinding technique at room temperature. 3-Aryl-5-(coumarin-3-yl)acylthio-1,2,4-triazoles on cyclisation with polyphosphoric acid using microwave irradiations under solvent free conditions give 2-aryl-5-(coumarin-3-yl)-thiazolo[3,2-<i style="mso-bidi-font-style: normal">b]­[1,2,4]triazoles 2a-h. The present method is quite environmentally benign as it avoids the use of hazardous organic solvents during the reaction as well as at working up stage. Several new compounds have been synthesized and their antibacterial properties have been described

Selective Halogenation of 1-(2-Hydroxyphenyl)-3-phenylpropane-1,3-diones Using Phase Transfer Catalysis and Synthesis of 3-Chloro- and 3-Bromo-flavones.

895-896Selective chlorination and bromination of 1-(2-hydroxyphenyl)- 3-phenylpropane-1,3-diones have been achieved by their reaction with ammonium chloride/ammonium bromide and hydrogen peroxide in biphase medium using phase transfer catalysis