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Reactions of indole-2,3-diones with biuret afforded 1,3-dihydro-3-ureidoformimido-2H-indol-2-ones and spiro[3H-indole-3,2′(1′H)-(1,3,5)triazine]-2,4′,6′(1H,3′H,5′H)-triones indicated these to be solvent dependent. The chemical structures of the products were elucidated by their comprehensive spectroscopic (IR, 1H-NMR, 13C-NMR, 19F-NMR, and Mass) as well as analytical analysis.

One pot green synthesis of 1-(1,2,4-triazol-4-yl)spiro[azetidine-2,3′-(3H)-indole]-2′,4′(1′H)-diones was carried out by the reaction of indole-2,3-diones,4-amino-4H-1,2,4-triazole and acetyl chloride/chloroacetyl chloride in ionic liquid [bmim]PF6 with/without using a catalyst. It was also prepared by conventional method via Schiff's bases, 3-[4H-1,2,4-triazol-4-yl]imino-indol-2-one. Further, the corresponding phenoxy derivatives were obtained by the reaction of chloro group attached to azetidine ring with phenols. The synthesized compounds were characterized by analytical and spectral (IR, 1H NMR, 13C NMR, and FAB mass) data. Evaluation for insecticidal activity against Periplaneta americana exhibited promising results.

A facile one-pot, three-component protocol for the synthesis of novel spiro[3H-indole-3,2′-thiazolidine]-2,4′(1H)-diones by condensing 1H-indole-2,3-diones, 4H-1,2,4-triazol-4-amine and 2-sulfanylpropanoic acid in [bmim]PF6 (1-butyl-3-methyl-1H-imidazolium hexafluorophosphate) as a recyclable ionic-liquid solvent gave good to excellent yields in the absence of any catalyst (Scheme 1 and Table 2). The advantages of this protocol over conventional methods are the mild reaction conditions, the high product yields, a shorter reaction time, as well as the eco-friendly conditions.

The reactions of 3-aroylmethylene-indol-2-ones with 2-hydrazinobenzothiazole in different media and solvent were investigated. The impact of substitution on indolyl nitrogen was also studied. The chemical structure of the products was proven on the basis of their spectral (IR, 1H-NMR, 13C-NMR, Mass) and analytical studies.

An efficient, facile and greener protocol for the synthesis of indole derivatives viz., 3′ H -spiro[indole-3,2′-[1,3]benzothiazole]-2(1 H )-ones, 6 H -indolo[2,3-b]quinoxalines and 3-(2-hydroxy-phenylimino)-1,3-dihydro-indol-2-ones, by the reactions of indole-2,3-diones with 1,2-difunctionalized benzene using tetrabutylammonium bromide (TBAB), as a surfactant under aqueous micellar media is described. This methodology has advantages of simple handling, mild reaction conditions and high yields of products in shorter reaction time as well as environmentally benign synthesis.

A greener, facile and efficient one-pot, three-component procedure for the synthesis of novel dispiropyrrolidine-bisoxindole derivatives by cycloaddition trapping of azomethine ylides generated in situ, via decarboxylative condensation of isatin with sarcosine (α-amino acid), has been reported in [bmim]PF6, an ionic liquid as a recyclable solvent in excellent yield without using any catalyst. This protocol provides mild reaction conditions, high yields of product in short reaction time, high regio- and stereoselectivity, operational simplicity and environmentally benign procedure.

2,4,6-Trichloro 1,3,5-triazine was selectively reacted with new nucleophilic reagents such as 4-methoxy-2-aminobenzothiazole, 2-chloro-4-trifluoromethyl-aniline, and phenylsubstituted thiourea in alkaline medium to give 2-(4-methoxybenzothiazol-2′-ylamino)-4-(phenylthioureido)-6-(substitutedthioureido)-1,3,5-triazines. The structures of these compounds were confirmed by IR, 1H NMR, 19F NMR, mass spectral data, and elemental analysis. The compounds show fungicidal activity against Alternaria alternata, Aspergillus niger, and Macrofomina. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

One pot green synthesis of 1-(1,2,4-triazol-4-yl)spiro[azetidine-2,3′-(3H)-indole]-2′,4′(1′H)-diones was carried out by the reaction of indole-2,3-diones,4-amino-4H-1,2,4-triazole and acetyl chloride/chloroacetyl chloride in ionic liquid [bmim]PF6 with/without using a catalyst. It was also prepared by conventional method via Schiff's bases, 3-[4H-1,2,4-triazol-4-yl]imino-indol-2-one. Further, the corresponding phenoxy derivatives were obtained by the reaction of chloro group attached to azetidine ring with phenols. The synthesized compounds were characterized by analytical and spectral (IR, 1H NMR, 13C NMR, and FAB mass) data. Evaluation for insecticidal activity against Periplaneta americana exhibited promising results.

Studies on the title reaction in different media indicate that ionic liquid [bmim]PF6 is a good solvent to achieve spiro[indole-pyrazole] (III) in excellent yield.

A facile one-pot, three-component protocol for the synthesis of novel spiro[3H-indole-3,2′-thiazolidine]-2,4′(1H)-diones by condensing 1H-indole-2,3-diones, 4H-1,2,4-triazol-4-amine and 2-sulfanylpropanoic acid in [bmim]PF6 (1-butyl-3-methyl-1H-imidazolium hexafluorophosphate) as a recyclable ionic-liquid solvent gave good to excellent yields in the absence of any catalyst (Scheme 1 and Table 2). The advantages of this protocol over conventional methods are the mild reaction conditions, the high product yields, a shorter reaction time, as well as the eco-friendly conditions.

Diones (I) are treated with amino substrates (II), (IV) or (VI) to form the different heterocyclic systems shown.

The azomethine ylide, generated in situ by decarboxylative condensation of isatin with sarcosine, undergoes 1,3-dipolar cycloaddition with dipolarophiles (I) in ionic liquid to give novel dispiro heterocycles with high regio- and stereoselectivity.

A new reagent N-hydroxy-N-(o-chlorophenyl)-N′-(p-methoxyphenyl)benzamidine hydrochloride, has been synthesized and is characterized on the basis of mp, elemental analysis, IR and UV spectra. The reactions of the reagent with metal ions suggest that new methods can be developed for gravimetric and extraction spectrophotometric determination of metal ions. The reagent has been successfully used for the extraction-spectrophotometric determination of vanadium(V) in presence of phenol. Many common ions including Co2+, Zn2+, Ag+, Mn2+, etc. do not interfere in the determination. The method has been applied for the determination of vanadium in steel samples.

Several fluorine-containing 9H-1,2,4-triazolo[4,3-a]benzimidazoles were synthesised using new methodology. 2-Hydrazinobenzimidazoles on acylation with acid anhydrides afforded 2-(acylhydrazino)benzimidazoles which, in turn, were cyclised with polyphosphoric acid to afford the title compounds. Representative compounds were screened for antibacterial, antifungal and herbicidal activities. The fluorinated derivatives showed enhanced antibacterial and antifungal activities on comparison to nonfluorinated analogues. Two of the derivatives showed 100% control of some grass weeds under pre-emergent conditions at 10 kg ha−1.

A new reagent N-hydroxy-N-(o-chlorophenyl)-N′-(p-methoxyphenyl)benzamidine hydrochloride, has been synthesized and is characterized on the basis of mp, elemental analysis, IR and UV spectra. The reactions of the reagent with metal ions suggest that new methods can be developed for gravimetric and extraction spectrophotometric determination of metal ions. The reagent has been successfully used for the extraction-spectrophotometric determination of vanadium(V) in presence of phenol. Many common ions including Co2+, Zn2+, Ag+, Mn2+, etc. do not interfere in the determination. The method has been applied for the determination of vanadium in steel samples.

Simple and N-substituted 3-aroylmethyleneindolin-2-ones (I) have been obtained by the reaction of indole-2,3-diones with methyl ketones followed by dehydration. The reaction of I with thiosemicarbazide has been investigated to study the effect of substitution on N atom

1-Trifluoroacetyl-3-dialkylaminomethyl-5-monosubstituted benzimidazoline-2-thiones have been synthesized from p-substituted anilines which were acetylated with trifluoroacetic acid. The trifluoroacetanilides were nitrated, reduced and cyclised with carbon disulphide in the presence of alcoholic potassium hydroxide and finally treated with formaldehyde and suitable secondary amines to afford the Mannich bases. The compounds were characterised by their analytical and spectral (ir, pmr, 19F and mass) data. The synthesized compounds have been screened for anti-inflammatory and analgesic activity and found to be active.

Reaction of 2-hydrazinobenzimidazoles with β-diketones in neutral and acidic media revealed that 2-(3,5-disubstituted-1H-pyrazol-1-yi)benzimidazoles are formed in the former case, whereas hydrazones are obtained in acidic medium. Further the alkylation of > NH of the title compound was investigated. Characterisation of these products have been done by elemental analysis, ir, pmr, 19F nmr, 13C nmr and mass spectral studies.