ChemInform Abstract: Cyclization Reactions of Electrochemically Generated o-(3-Butenyl)phenyl Anions and Radicals to 1-Methylindan (original) (raw)
Journal of the American Chemical Society, 1986
0.8 e ,k3 were found in the final difference Fourier map very near the methyl carbons of the diethylaluminum moiety. All other peaks were less than 0.6 e .k3. All calculations were carried out on a VAX 11/750 computer with the CRYRM system of programs. [Cp2Zr(C,0-~2-OCCHCH2CMe3)]z(p-H)(p-AIEt2) (X). A toluene solution of Ia (1.057 g, 1.58 mmol) was treated with several equivalents (0.400 mL, 3.77 mmol) of neat Et2A1H. A deep yellow solution formed and was stirred for 24 h at 80 OC. Removal of solvent in vacuo afforded a dark brown waxy residue that was washed with four 15-mL portions of cold (-30 "C) hexane to yield X as a white powder (0.444 g, 0.589 mmol). The dark brown washings were evacuated to dryness, redissolved in toluene, and stirred at 80 OC for an additional 6 h. Workup in a similar manner provided an additional 0.094 g (0.125 mmol) of X. Recrystallization of 0.100 g of X from 5 mL of Et,O-hexane (3/2) at-20 OC afforded crystals suitable for X
Electrophilic reactions of 4-methyl-A-homo-4-azacholest-4a-en-3-one
Tetrahedron, 1997
Nitration, bromination and oxidation reactions of 4-methyI-A-homo-4-azacholest-4a-en-3-one (1) were studied. The reaction with acetyl nitrate gave products of cis addition to the double bond accompanied by the A-seco compounds. The results of bromination were dependant on the reaction conditions. After the initial electrophilic attack at C-5, further transformations involved the addition of a nucleophile, which was followed by isomerization to the A-seco compounds or rearrangement to the six-membered lactams or lactone promoted by AgBF4. The CrO3 oxidation yielded the product of a double bond cleavage.
Ring forming reactions of some amineimides with a note on electrophilic bromination
Canadian Journal of Chemistry, 1979
Allylic and propargylic amineimides react with bromine to form 4H-1,3,4-oxadiazinium salts in accord with recent studies of electrophilic brominations. A novel synthesis of 5,6- dihydro-4,4-dimethyl-6-hydroxymethyl-2-phenyl-4H-1,3,4-oxadiazinium bromide by the reaction of N′N′-dimethylbenzohydrazide and epibromohydrin is reported.
1,6-Electrocyclization of 1-Azatriene Derivatives
European Journal of Organic Chemistry, 2008
quinolinium mesylate (10) readily reacted with α,β-unsaturated aldehydes to afford 1-azatrienes 12a-h, which could be cyclized to give 6,7-dihydro-4H-benzo[a]quinolizines 14a-h. Scheme 1. Reactions of 1 with aldehydes.
2015
School of Studies in Chemistry, Jiwaji University, Gwalior-474 011, Madhya Pradesh, India E-mail : rajeevjain54@yahoo.co.in School of Studies in Environmental Chemistry, Jiwaji University, Gwalior-474 011, Madhya Pradesh, India Manuscript received online 30 October 2014, accepted 27 November 2014 A new series of 4-[(<em>E</em>)-{[(4-substituted]sulfonyl]substitutedimino}methyl](substituted)phenyl acetate were synthesized by coupling of 3-methoxy-4-acetyloxy benzaldehyde with different sulphanalamide derivatives. Electrochemical behaviour of 4-[(<em>E</em>)-{[(4-substituted]sulfonyl]substitutedimino}methyl](substituted)phenyl acetate have been studied in Britton-Robinson buffers of pH 2.5–12.0 at dropping mercury and glassy carbon electrode. All the synthesized compounds gave 2-electron wave corresponding to the reduction of -N=N- bonds at mercury electrode. On the basis of differential pulse polarography, cyclic voltammetry, IR, mass and <sup>1</sup&...
Journal of Heterocyclic Chemistry, 2009
Electrochemical oxidation of 2,3-dimethylhydroquinone 1 has been studied in the presence of o-phenylenediamines 3a-c as nucleophiles in aqueous solution, using cyclic voltammetry and controlled potential coulometry. The results indicate that the quinone 2 derived from 2,3-dimethylhydroquinone participates in Michael addition and imine condensation reactions with o-phenylenediamine via an ECECC mechanism, and is converted to the corresponding phenazine derivatives 7a-c and 7 0 b. The electrochemical synthesis of compounds 7a-c and 7 0 b has been performed successfully at a carbon rod electrode in an undivided cell with good yields and high purities.
Electrochemical syntheses of heterocyclic compounds-IV. Syntheses with nascent quinones
Tetrahedron Letters, 1976
Anodic oxidations of chatcone phenylhydrazone were performed in acctonitrlle-lithium pcrchlorate electrolyte solution at platinum using controlled potentials. By means of TLC the following products were isolated: 1.3,5-triphenylpyrazole (I). l-3.5-triphenyl-A'-pyrazoline (2~). 1,3,5-triphenyl-A'pyrazolinium perchlorate (_'), 4.4'-bis[3.5-diphenyI-h'-pyrazolynil-(l)]-biphenyl (3~2). protonated form of the compound 3a as a diperchlorate (3) and 4.4'-bis-[3.5-diphenylpyrazolyl-(I)]-biphenyl (4). A mechanism rationalizing these products as well as cyclic voltammetric and chronoamperometric data is proposed. the proposed reaction Scheme and with 830. 760 cm-' ; mass spectrum m/e (relative intenresults previously reported on the oxidation of the sity): 795 (8). 297 (23). 296 (IOO), 295 (50), 268 (4). 192 substituted pyrazolines[16]. (16.5), 165 (15). 152 (5). 106 (27), 105 (49), 77 (25). R. L. Hand and R. F. N&on, J A,n r&m. Sot 96. 850 (I 974).
ChemInform, 2014
Reaction of activated methylene compounds with 2-aminomethylene-1,3-dicarbonyl compounds as 1,3-bis-electrophilic 3C-synthons is a very popular method for the synthesis of various azines (for reviews, see [1]). Amongst the most readily available enaminodicarbonyl substrates of this type are the 2-anilinomethylene derivatives of 1,3-dicarbonyl compounds which are readily synthesized through a three-component condensation of an activated methylene compound, triethylorthoformate, and aniline .
Tetrahedron Letters, 1976
the realization of this objective , as well as the synthesis of 2,3,6,7-dibenzobicyclo[6.2.O]deca-2,4.6,8-tetraene-9,10-dione (41, in which cyclobutenedione is fused to a nonplanar conjugated eight-membered ring. It is known that the [2+2lcycloaddition of dichloroketene to nonactivated acetylenes proceeds weii oniy when tie triple bond is strained. 5 ,fie acetyienes in r are strained, 2 and reaction of this substance with an excess of dichloroketene (generated in situ from dichloroacetyl chloride and triethylamine) 6 in pentane at 20D 7 for 12 hr gave 42% of the monoadduct 2
Acta poloniae pharmaceutica
Coumarins have been reported to possess wide variety of biological activities like anti-inflammatory (1), anticonvulsant (2) and antitumor (3). The 1,3,4oxadiazole derivatives are reported to show a broad spectrum of biological activities, which include antibacterial (4), anti-inflammatory (5), anticonvulsant (6, 7), CNS stimulant (8) and antihypertensive (9). The 1,3,4-thiazolidinone derivatives also possess activities like antibacterial (10), anticonvulsant (11), antifungal (12), antihistaminic (13) and anti HIV (14). This prompted us to synthesize and study the antimicrobial activity of compounds incorporating coumarin, 1,3,4oxadiazole and 1,3,4-thiazolidinone moieties: EXPERIMENTAL All the solvents were of LR grade and were obtained from Merck, CDH and S. D. Fine Chemicals. Melting points were determined in open capillary tubes and are uncorrected. Thin layer chromatography was performed on silica gel G (Merck). The FT-IR spectra were recorded in KBr pellets on a BIO-RAD FTS 135 WIN-IR spectrophotometer. 1 H-NMR and 13 C NMR spectra were recorded on a Bruker model DPX 300 FT NMR spectrometer in (DMSO-d 6) using tetramethylsilane (Me 4 Si, TMS) as an internal standard. Mass spectra were recorded at 70 eV on a Jeol JMS-D instrument fitted with a JMS 2000 data system,. All the structures of the compounds were drawn with the help of ChemDraw Ultra 9.0 (ChemOffice 2005 software). Synthesis of ethyl-2-oxo-2H-chromene-3-carbxylate 1 (m.p. 120ñ122∫C), 2-oxo-2H-chromene-3carbohydrazide 2 (m.p. 136ñ138∫C), 3-(5-amino-1,3,4-oxadiazol-2-yl)-2H-chromen-2-one 3 (m.p. 200ñ202∫C) and 3-(5-{[substituted phenyl)methylene]amino}-1,3,4-oxadiazol-2-yl)-2H-chromen-2ones 4 were carried out by reported methods (15ñ17). General method of synthesis of 2-(substituted phenyl)-3-[5-(2-oxo-2H-chromen-3-yl)-1,3,4-oxadiazol-2-yl]-1, 3-thiazolidin-4-ones (5a-m) (Scheme 1) 13-(5-{[Substituted phenyl)methylene]ami-no}-1,3,4-oxadiazol-2-yl)-2H-chromen-2-one 4 (0.01 mol) and mercaptoacetic acid (0.9 g, 0.01 mol) were refluxed in the presence of catalytic amount of ZnCl 2 in dry 1,4-dioxane (25 mL) for 12 h. Then, the reaction mixture was cooled and poured onto crushed ice. The separated out product 5 was filtered, dried and crystallized from ethanol. The other compounds of the series were synthesized similarly. 2-(3-Nitrophenyl)-3-[5-(2-oxo-2H-chromen-3-yl)-1,3,4-oxadiazol-2-yl]-1,3-thiazolidin-4-one (5a) Yield: 60%; m.p. 178ñ180 O C; R f 0.73; IR (KBr, cm ñ1): 3000 (C-H), 2700 (N= C-H). 1680 (C=O,
ChemInform Abstract: Ring Closure Reaction of 4-tert-Butyl-4-penten-1-ol with Electrophilic Reagents
ChemInform, 2010
The reaction of 4-tert-butyl-4-penten-l-ol 3 with some electrophilic reagents (such as mineral acids, mercuric acetate, peracids) has been investigated. It is found that in the acid (H 2 S0 4) catalysed reaction of 3, the products of 1,2methyl rearrangement are produced. The oxymercuration/demercuration reaction of 3 and its reaction with metachloroperbenzojc acid afford in high yields exclusively Markovnikov-type products.
Electrochemical studies on haloamides. Part XII. Electrosynthesis of oxazolidine-2,4-diones
Tetrahedron, 1995
Electrogenerated bases promote the carboxylation of NH-protic carboxamides bearing a leaving group at the position 2 to give oxazolidine-2,4-diones. The process is believed to involve acidbase reaction with the substrate, carboxylation of its conjugate base to the corresponding carbamate and ring-closure following inlramolecular SN 2 reaction. A variety of oxazolidine-2,4-diones, including clinically used trimethadione @ and malidone @, have been prepared in high to excellent yield, which established the scope and generality of this new ring-forming process.
SYNTHESIS AND ANTIBACTERIAL EVALUATION OF NOVEL HETEROCYCLIC COMPOUNDS
The work describes QSAR and SAR studies on the reserve transcriptase inhibitor by using the 2D-topological, physicochemical and hydrophobic parameters along with the indicator parameters. For the synthesis of new heterocyclic compounds containing a sulfonamido moiety suitable for use as antibacterial agents, the precursor ethyl {[4-N-(4,6-dimethylpyrimidin-2-yl)sulfamoyl] phenylazo}cyanoacetate was reacted with a variety of active methylene compounds producing pyran, pyridine and pyridazine derivatives. Also, the reactivity of the precursor hydrazone towards hydrazine derivatives to give pyrazole and oxazole derivatives was studied. On the other hand, treatment of the same precursor with urea, thiourea and/or guanidine hydrochloride furnished pyrimidine and thiazine derivatives, respectively. The newly synthesized compounds were tested for antibacterial activity, whereby eight compounds were found to have highactivities
Bioorganic & Medicinal Chemistry Letters, 2007
Discovery of novel antibacterial agents is a significant challenge. We have recently reported on our discovery of novel antibacterial agents in which we have rapidly optimized potency utilizing a parallel chemistry approach. These advanced leads suffer from high affinity for human serum albumin (HSA). In an effort to decrease the affinity for HSA we have prepared a series of heterocyclic analogs, which retained antibacterial activity and demonstrated reduced affinity for HSA.