Improved Radical Approach to N-Unsubstituted Indol-2-one and Dihydro-2-quinolinone Compounds Bearing Spirocyclic Cyclohexanone/Cyclohexadienone Rings (original) (raw)
Related papers
Oxidative Ring Expansion of Spirocyclic Oxindole Derivatives
The Journal of Organic Chemistry, 2014
Oxidation of the spirocyclic oxindole derivative, isamic acid 1, led to decarboxylation and ring expansion to quinazolino[4,5-b]quinazoline-6,8-dione 7 rather than, as previously believed, its isomer 6. The structure of 7 was confirmed by X-ray crystallography. Condensation of isatin (indole-2,3-dione) and 2-aminobenzamide led to the spirocyclic molecule, spiro[3H-indole-3,2′(1H)quinazoline]-2,4′(1H,3H)dione 8, which was also identified as an intermediate in the oxidation of isamic acid. Mild hydrolysis of 7 gave the 10-membered molecule 22. Isamic acid could easily be converted to N-nitrosoisamic acid, which when heated in ethanol underwent a ring expansion to a hydroximino derivative, 38, of compound 6. The structure of 38 was confirmed by X-ray crystallography.
Investigation and Synthesis of Some Novel Spiro Heterocycles Related to Indoline Moiety
Journal of Scientific Research, 2014
Reactions of indole-2,3-dione 1 with 2-mercaptobenzimidazole, o-phenylenediamine, 2-aminophenol, 2-aminobenzothiazole, 2-aminobenzimidazole and 3-methyl-1-phenyl-2-pyrazolin-5-one were carried out to give compounds spiroindolethiazetobenzimidazole 2, spirobenzimidazole(oxazole)indoline 3a,b, benzothiazol(imidazol) iminoindolinone 4a,b and methyloxoindolylidenepyrazolone 5 respectively. Compound 5 was reacted with 2-aminophenol as well as o-phenylenediamine to give new spirooxazepine and diazepine derivatives 6a,b respectively. Reaction of 5 with nitrogen nucleophiles as well as carbon nucleophiles was investigated to furnish new spiro heterocycles 7-11. The reaction of 2-(2-oxo-1,2-dihydroindol-3-ylidene)malononitrile compound 12 with 3-methyl-1-phenyl-2-pyrazoline-5-one was carried out to give spiroindolopyranopyrazolo derivative 13. Compounds 4a,b was reacted with thioglycolic acid to give thiazolidinone derivatives 14a,b. Epoxidation of 5 using monoperoxyphthalic acid magnesium s...
Synthesis, 2004
Aryl radical cyclization of a range of 6-(2¢-bromophenoxymethyl)-1,3-dimethyluracils 4a-g was carried out with tributyltin chloride and sodium cyanoborohydride in the presence of AIBN for four hours to give exclusively the '5-exo' cyclization products, 1,3-dimethylspiro[pyrimidine-6,3¢-2¢,3¢-tetrahydrobenzofuran]-2,4-diones 5a-g in 92-95% yield. The starting materials were in turn prepared in 90-92% yield by refluxing 6-chloro methyl-1,3dimethyl uracil with various 2-bromophenols or 2-bromonaphthol in acetone in the presence of anhydrous potassium carbonate for eight hours.
Molecules
Spirocyclic nitroxyl radicals (SNRs) are stable paramagnetics bearing spiro-junction at α-, β-, or γ-carbon atom of the nitroxide fragment, which is part of the heterocyclic system. Despite the fact that the first representatives of SNRs were obtained about 50 years ago, the methodology of their synthesis and their usage in chemistry and biochemical applications have begun to develop rapidly only in the last two decades. Due to the presence of spiro-function in the SNRs molecules, the latter have increased stability to various reducing agents (including biogenic ones), while the structures of the biradicals (SNBRs) comprises a rigid spiro-fused core that fixes mutual position and orientation of nitroxide moieties that favors their use in dynamic nuclear polarization (DNP) experiments. This first review on SNRs will give a glance at various strategies for the synthesis of spiro-substituted, mono-, and bis-nitroxides on the base of six-membered (piperidine, 1,2,3,4-tetrahydroquinoline...
Synthesis of spiro[indoline-3,4′-pyrano[3,2-c]quinolone]-3′-carbonitriles
Monatshefte für Chemie - Chemical Monthly
Quinoline-2,4-diones reacted with 2-(2-oxo-1,2-dihydroindol-3ylidene)malononitrile in pyridine to give 2'-amino-2,5'-dioxo-5',6'-dihydrospiro(indoline-3,4'-pyrano[3,2-c]quinoline)-3'-carbonitriles in good to excellent yields. The structures of all new products were proven using one-and twodimensional NMR, IR, and mass spectral data, and in four cases X-ray structural analyses. The possible mechanism for the reaction is also discussed. MCCM_Template_Vers 4