Reissert-Henze Reaction Research Articles

Synthesis and reactions of [1]benzofuro[3,2-c]pyridine

(E)-3-(1-Benzofuran-2-yl)propenoic acid (I) was prepared from 1-benzofuran-2-carbaldehyde under the Doebner’s conditions. The obtained acid was converted to the corresponding azide II, which was cyclized by heating in diphenyl ether to [1]benzofuro[3,2-c]pyridin-1(2H)-one (III). This compound was aromatized with phosphorus oxychloride to chloroderivative IV which was reduced with zinc and acetic acid to the title compound V. [1]Benzofuro[3,2-c]pyridin-2-oxide (VI) was synthesized by reaction of V with 3-chloroperoxybenzoic acid in dichloromethane. Treatment VI with benzoyl chloride and potassium cyanide (Reissert-Henze reaction) was shown to produce the corresponding [1]benzofuro[3,2-c]pyridin-1-carbonitrile (VII). The title compound was used for preparation of complex compounds VIII, IX

ChemInform Abstract: Functionalization of a Pyridine Framework Through Intramolecular Reissert—Henze Reaction of N‐(Carbamoyloxy)pyridinium Salts and Unexpected Insertion of Ethereal Solvents.

Abstract2‐Pyridyl carbamates are synthesized involving a new intramolecular transformation of an acyloxy group from N‐carbamoyloxypyridinium salts as key step.

Functionalization of a Pyridine Framework through Intramolecular Reissert–Henze Reaction of N‐(Carbamoyloxy)pyridinium Salts and Unexpected Insertion of Ethereal Solvents

AbstractA new strategy for synthesis of the 2‐pyridyl carbamates is reported. This strategy exploits a new intramolecular transformation of an acyloxy group from N‐carbamoyloxypyridinium salts (Reissert–Henze‐type reaction) as the key step. Addition of a silver salt effectively accelerates the intramolecular attack of the carbonyl oxygen at the 2‐position of the pyridine ring. Additionally, a new rearrangement of the acyloxy group, combined with insertion of an ethereal solvent to give pyridine derivatives having a coordinating tether, is reported.

ChemInform Abstract: Metal Free Quick Introduction of Azole in to Azine Nucleus: Acid Catalyzed Reissert—Henze Reaction.

AbstractOptimum reaction conditions are examined for the reaction of N‐tosylimidazoles derivatives (II) or (X) with pyridine, quinoline or isoquinoline N‐oxides to give the corresponding imidazole‐substituted N‐heterocycles.

Metal Free Quick Introduction of Azole in to Azine Nucleus: Acid Catalyzed Reissert-Henze Reaction

E-mail: velavana@shasun.com; veluvaisu@gmail.comReceived June 13, 2013, Accepted August 1, 2013Key Words : Amberlyst-15, Pyridine- N-Oxide, Imidazole, Reissert-Henze reaction, Acid catalyzedImidazole appended heterocycle moieties are commonlyencountered in biologically important molecules. Imidazolesubstituted in 2

ChemInform Abstract: Regioselective Functionalization of 1H-Pyrrolo(2,3-b)pyridine via Its N-Oxide.

Selective functionalization of 1H-pyrrolo[2,3-b]pyridine (7-azaindole) at the 6-position was achieved by Reissert-Henze type reaction. Thus, halogeno (Cl, Br, I), cyano and thiocynato groups were directly introduced to the pyridine ring of 7-azaindole

1]Benzofuro[3,2-c]pyridine synthesis and coordination reactions

(E)-3-(1-Benzofuran-2-yl)propenoic acid (1) was prepared from 1-benzofuran-2-carbaldehyde under the Doebner’s conditions. The obtained acid was converted to the corresponding azide 2, which was cyclized by heating in diphenyl ether to [1]benzofuro[3,2-c]pyridine-1(2H)-one (3). This compound was aromatized with phosphorus oxychloride to chloroderivative 4 which was reduced with zinc and acetic acid to the title compound 5. [1]Benzofuro[3,2-c]pyridine-2-oxide (6) was synthesized by reaction of 5 with 3-chloroperoxybenzoic acid in dichloromethane. Treatment of 6 with benzoyl chloride and potassium cyanide (Reissert-Henze reaction) was shown to produce the corresponding [1]benzofuro[3,2-c]pyridine-1-carbonitrile (7). The title compound was used for preparation of complexes Cu2(ac)4(bfp)2 (8) and CoCl2(bfp)2 (9), where ac=CH3CO2− and bfp=[1]benzofuro[3,2-c]pyridine. Both oxygen atom of carboxylate ions is used in the coordination to Cu(II). Thermal properties of the complexes 8 and 9 have been studied by TG and DTA and both complexes exhibited high thermal stability while complex 9 are thermally more stable than complex 8.

Synthesis and reactions of 2-[3-(trifluoromethyl)phenyl]furo[3,2-c]pyridine

Abstract(E)-3-{5-[3-(Trifluoromethyl)phenyl]furan-2-yl}propenoic acid (I) was prepared from 5-[3-(tri-fluoromethyl)phenyl]furan-2-carbaldehyde under the Doebner’s conditions. The obtained acid was converted to the corresponding azide II, which was cyclized by heating in diphenyl ether to 2-[3-(trifluoromethyl)phenyl]-4,5-dihydrofuro[3,2-c]pyridin-4-one (III). This compound was aromatized with phosphorus oxychloride to chloroderivative IV which was reduced with H2NNH2-Pd/C to the title compound V. 2-[3-(Trifluoromethyl)phenyl]furo[3,2-c]pyridin-5-oxide (VI) was synthesized by reaction of V with 3-chloroperoxybenzoic acid in dichloromethane. On treatment of VI with benzoyl chloride and potassium cyanide (Reissert-Henze reaction), corresponding 2-[3-(trifluoromethyl)phenyl]furo[3,2-c]pyridine-1-carbonitrile (VII) resulted. 5-Amino-2-[3-(trifluoromethyl)phenyl]furo[3,2-c]pyridin-5-ium-4-methylbenzene sulfonate (VIII) was prepared by direct N-amination of the title compound V with 1-[(aminooxy)sulfonyl]-4-methylbenzene in dichloromethane. Then, VIII was transformed to a non-isolated zwitterionic N-imid IX which afforded the corresponding furo[3,2-c]pyrazolo[1,5-a]pyridine carboxylic acid esters X, XI by 1,3-dipolar cycloaddition reactions with dimethyl but-2-ynedionate (DBD) or ethyl propiolate. The structures of all compounds were confirmed by their IR and NMR spectra.

The First Practical and Efficient One-Pot Synthesis of 6-Substituted 7-Azaindoles via a Reissert-Henze Reaction

A variety of 6-substituted 7-azaindoles (30 examples) were obtained via selective O-methylation of 7-azaindole- N-oxide M-chlorobenzoic acid salt and subsequent, base-catalyzed one-pot reaction with a range of N-, O-, S-nucleophiles or cyanide.

Chelate [2‐(Iminoethyl)pyridine N‐oxide]metal Complexes – Synthesis and Structural Comparison with Their Chemically Related 2‐(Iminoethyl)pyridine‐Derived Systems

AbstractThe N,O‐chelate ligands 2‐(iminoethyl)pyridine N‐oxide (2a) and 2‐(iminoethyl)‐6‐isopropylpyridine N‐oxide (2b) were prepared by conventional synthetic routes, the latter involving a variant of the Reissert–Henze reaction. Treatment of 2a with FeCl2 resulted in a deoxygenation reaction of the ligand and formation of the salt [bis{2‐(iminoethyl)pyridine}FeCl]+[FeCl4]– (18a). In contrast, the reaction of 2a with PdCl2 or CoCl2 cleanly furnished the six‐membered chelate [κN,O‐2(iminoethyl)pyridine N‐oxide]MCl2 complexes (19a, M = Pd) or (20a, M = Co), respectively, which were both characterised by X‐ray diffraction. Treatment of 2b with [NiBr2(dme)], followed by crystallisation from THF, gave the complex [(κN,O‐2b)NiBr2(THF)] (21b), which features a distorted trigonal‐bipyramidal coordination geometry of the central metal atom. The reaction of 2a with [NiBr2(dme)] gave the structurally related complex [(κN,O‐2a)NiBr2(κO‐2a)] (21a). The N,O‐chelate Pd complex 19a was shown to be an active catalyst for the Suzuki coupling reaction. The ligand systems 2a,b and their related 2‐(iminoethyl)pyridines 3a,b and a variety of metal complexes of ligands 3 were also prepared and characterised for comparison by X‐ray diffraction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

Synthetic Studies on Thiostrepton Family of Peptide Antibiotics: Synthesis of the Tetrasubstituted Dihydroquinoline Portion of Siomycin D1

The tetrasubstituted dihydroquinoline portion of siomycin D 1 , a member of the thiostrepton family of peptide antibiotics, was synthesized from 5,6,7,8-tetrahydroquinoline featuring the modified Reissert-Henze reaction, the homolytic aromatic substitution reaction, the modified Boekelheide rearrangement, and the Jacobsen asymmetric epoxidation.

5-Aminofuro[3,2-c]pyridinium Tosylates and Substituted Furo[3,2-c]pyridine N-Oxides: Synthesis and Reactions

5-Aminofuro[3,2-c]pyridinium tosylates 2a-2c were synthesized by direct N-amination of furo[3,2-c]pyridines 1a-1c with O-(4-methylbenzenesulfonyl)hydroxylamine in dichloromethane. Zwitterionic furo[3,2-c]pyridinium N-imides 3a-3c generated from 2a-2c and anhydrous potassium carbonate in N,N-dimethylformamide afforded by 1,3-dipolar cycloaddition reactions with dimethyl butynedioate or ethyl propiolate the corresponding furo[3,2-c]pyrazolo[1,5-a]pyridinecarboxylic esters 4a-4c and 5a-5c. Furo[3,2-c]pyridine N-oxides 6a-6c and their benzo derivative 6d were synthesized by reaction of 1 with 3-chloroperbenzoic acid in dichloromethane. Treatment of N-oxides 6 with benzoyl chloride and cyanide anion (Reissert-Henze reaction) was shown to produce the corresponding furo[3,2-c]pyridine-4-carbonitriles 7. In further transformations (acid and alkaline hydrolysis), the cyano group was converted successively to amide and carboxylic acid.

A general synthetic route for 1-substituted 4-oxygenated β-carbolines (Synthetic studies on indoles and related compounds 41)

A new synthetic route for two naturally accuring 1-substituted 4-methoxy-β-carbolines ( 1b, c) is described. This synthetic route involves elaboration of the ester groups in ethyl indole-2-carboxylate ( 4b) and its 1-benzyl derivative ( 4a), C 3-selective cyclization of the substituent at the C 2-position of the indole nucleus, and functionalization at the C 1-position of the β-carboline nucleus by a modified Reissert-Henze reaction. The synthetic β-carbolines ( 1b, c) should be key intermediates for the synthesis of their congeners, leading to a general synthetic route of 1-substituted 4-oxygenated β-carbolines.

Synthesis of 14C-labelled CGS 19755, a selective NMDA antagonist

CGS 19755 is a selective NMDA (N-methyl-D-aspartate) antagonist presently under development as a neuronal protecting agent after stroke and head trauma. It was synthesized with 14C-labelling in the carboxylic acid side chain via the synthetic route displayed in Scheme 1. Key steps in the synthesis involved a Reissert-Henze addition of potassium [14C]cyanide to a functionalized pyridine N-oxide, followed by hydrolysis and a selective hydrogenation affording the desired cis-substituted piperidine target. Using this procedure, [14C]CGS 19755 was prepared with radiochemical purity of 99.6%. The synthesis demonstrates the utility of the Reissert-Henze reaction, in conjunction with palladium/rhodium-catalyzed hydrogenation, as a facile means of preparing 14C-labelled cis-2,4-substituted cyclic amino acids.

Studies on pyrimidine derivatives. XXXIX. Site-selectivity in the reaction of 5-substituted and 4,5-disubstituted pyrimidine N-oxides with trimethylsilyl cyanide.

The site-selectivity in the modified Reissert-Henze reaction of 5-substituted, and 4, 5-disubstituted pyrimidine 1-oxides with trimethylsilyl cyanide was examined. The reaction of 5-substituted 4-methoxypyrimidine 1-oxides with trimethylsilyl cyanide gave exclusively 2-pyrimidine-carbonitriles in good yields without exception. On the other hand, the other 5-substituted and 4, 5-disubstituted pyrimidine 1-oxides gave mainly 6-pyrimidinecarbonitriles.

Regioselective cyanation of pyridine 1-oxides with trimethylsilanecarbonitrile: a modified Reissert-Henze reaction

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRegioselective cyanation of pyridine 1-oxides with trimethylsilanecarbonitrile: a modified Reissert-Henze reactionWilmer K. FifeCite this: J. Org. Chem. 1983, 48, 8, 1375–1377Publication Date (Print):April 1, 1983Publication History Published online1 May 2002Published inissue 1 April 1983https://doi.org/10.1021/jo00156a053RIGHTS & PERMISSIONSArticle Views2765Altmetric-Citations110LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (428 KB) Get e-Alerts Get e-Alerts

New Methods and Reagents in Organic Synthesis. 12. Reaction of Diethyl Phosphorocyanidate(DEPC) with Aromatic Amine Oxides. A Modified Reissert-Henze Reaction

New Methods and Reagents in Organic Synthesis. 12. Reaction of Diethyl Phosphorocyanidate(DEPC) with Aromatic Amine Oxides. A Modified Reissert-Henze Reaction

ChemInform Abstract: STUDIES ON TERTIARY AMINE OXIDES. LXI. SOME REACTIONS OF 2‐PHENYLQUINOLINE 1‐OXIDE AND ITS DERIVATIVES

AbstractDie Nitrierung des Chinolin‐N‐oxids (I) ergibt in Abhängigkeit von der Schwefelsäure‐Konzentration die Produkte (II) und (III), aus (III) (X=H) wird mit PCl3 (IV) erhalten.

Studies on tertiary amine oxides. LXI. Some reactions of 2-phenylquinoline 1-oxide and its derivatives.

The orientation of nitration of 2-phenylquinoline 1-oxide (1) with potassium nitrate and sulfuric acid was found to be principally governed by the concentration of sulfuric acid independently of the reaction temperature. Thus, whereas the reaction in concentrated sulfuric acid gave 3'-nitro derivative (3) as the main product, the use of 70-75% sulfuric acid was favorable for the formation of 4-nitro derivative (2). Further nitration of 2 and 3 readily produced 3', 4-dinitro compound (4). The Reissert-Henze reaction of 2-(4-methoxyphenyl) quinoline 1-oxide (7) afforded 1-benzoyloxy-4-cyano-1, 4-dihydroquinoline (12) besides 4-cyano (9), 6-benzoyloxy- (10) and 8-benzoyloxy-quinolines (11). From the reaction of 2-(4-nitrophenyl) quinoline 1-oxide (8), the corresponding 1, 4-dihydroquinoline (15) was also isolated together with 6-and 3-benzoyloxyquinolines (13 and 14). The mechanism of the formation of benzoyloxy derivatives was discussed.

Reactions of Heteroaromatic N-Oxides with Acid Chloride in the Presence of Potassium Cyanide (The Extension of the Reissert-Henze Reaction)

Reactions of Heteroaromatic N-Oxides with Acid Chloride in the Presence of Potassium Cyanide (The Extension of the Reissert-Henze Reaction)