Markus Vettel

Eine neue, breit anwendbare Synthese für aromatische Aldehyde

Diformamide (1) reacts with activated aromatic compounds like toluene, anisole, m-xylene, 1,2-dimethoxybenzene in the presence of AlCl3 to give N-(diarylmethyl)-formamides 2a—d, the corresponding aromatic aldehydes 3—6 are formed as by-products in low yields. From N,N-dimethylaniline and 1/AlCl3 the triphenylmethane derivative 7 can be obtained. The reaction of anisole with N-methyl-diformamide (9) affords the formamide 10. The mixture of formamide, P4O10 and AlCl3 reveals to be a reagent which is capable to formylate toluene and anisole, resp. Triformamide (14)/AlCl3 is an effective formylating system which allows the preparation of aromatic aldehydes (e.g.3,4,17—32) from the corresponding aromatic hydrocarbons. Aluminiumchloride can be replaced by borontrichloride. The yields of the formylation reactions depend strongly from the reaction conditions (molar ratio: aromatic hydrocarbon/AlCl3/14; solvent, reaction temperature). The scope of the reaction covers nearly complete those of the Gattermann-Koch-, Gattermann- and Vilsmeier—Haack-reaction.

Orthoamide und Iminiumsalze, XCIII. Darstellung und Umsetzungen eines vinylogen Orthoamid-Derivats der Kohlensäure mit CH2-aciden Verbindungena

Abstract The preparation of the vinylogue guanidinium salt 10c is described. The reaction of the vinylogue orthocarbonic acid amide derivative 12 with CH2-acidic compounds 14a–s affords the ketene aminals 15a–s. At room temperature the succinimide 19a is deprotonated by 12 to give the vinylogue salt 10e. The bis-ketene aminal 20 is formed in the reaction of 19a with 12 at elevated temperatures. Succinic acid esters 21 do not react cleanly with the orthoamide 12, but mixtures of ketene aminals 23 and bis-ketene aminals 22 are formed. From succinodinitrile (24) and 12 the bis-ketene aminal 25 could be obtained, which is also accessible by the action of the salt 10c with 24 in the presence of sodium hydride.

Orthoamide und Iminiumsalze, LXXVI [1]. Ein weiterer Beitrag zur Chemie der Trialkoxyacetonitrile/ Orthoamides and Iminium Salts LXXVI [1]. A Further Contribution to the Chemistry of Trialkoxyacetonitriles

An improved procedure for the preparation of trimethoxyacetonitrile (3a) starting from trichloroacetonitrile and sodium methanolate is described. Carbanions, obtained by the action of sodium hydride on nitriles, ethyl acetate and methylketones, react with trialkoxyacetonitriles 3 to give α- imino-orthocarboxylic acid trialkylesters 12, 14 and 20, which form an equilibrium with the tautomeric enamines 13, 15 and 21. The enamines 21 react with N,N-dimethylformamide dimethylacetal (24) to give amidines 25 which are cyclized to pyridinium salts 28 and 29 on treatment with benzyl bromide and acetyl chloride, respectively. The reaction of the enaminonitrile 13a with the orthoamide derivative of phenylpropiolic acid 30 affords the pyridine-2-orthocarboxylic acid trimethylester 31. The N,O-protected 4-hydroxy-piperidine 35 can be deprotonated by means of sec-butyl lithium. The carbanions thus formed are trapped with D2O, dimethyl sulfate, phenylisocyanate, CO2, and dimethyl carbonate delivering the piperidine derivatives 37 - 41. The heterocyclic orthoester 43 can be prepared analogously from 35 and 3a. The piperidine derivatives 44, 46 and 47 are prepared from the N,O-protected piperidines 39 and 41. Graphical Abstract Orthoamide und Iminiumsalze, LXXVI [1]. Ein weiterer Beitrag zur Chemie der Trialkoxyacetonitrile/ Orthoamides and Iminium Salts LXXVI [1]. A Further Contribution to the Chemistry of Trialkoxyacetonitriles

Orthoamide, LXV [1]. Kondensationsreaktionen von Amidinen, Guanidinen, Hydrazin und Hydrazin-Derivaten mit Orthoamiden von Alkincarbonsäuren / Orthoamides,LXV [1]. Condensation Reactions of Amidines, Guanidines, Hydrazine and Hydrazine Derivatives with Orthoamides of Alkyne Carboxylic Acids

The orthoamide derivatives 4 react with amidines 10 and guanidines 11 to give 4-dimethylaminopyrimidines 12. The 3-dimethylamino-pyrazoles 13a - c can be prepared from orthoamides 4 and hydrazine. The hydrazine derivative 14, whose constitution was established by crystal structure analysis, is obtained in low yield when hydrazine is added dropwise to a boiling solution of 4d in THF. Methyl- and phenylhydrazine, undergo reaction with the orthoamides 4a, c yielding mixtures of the isomeric pyrazoles 19 and 20. The reaction of 4c with acylhydrazines 21a - e affords the pyrazole 13b. The pyrazole 26 is produced in the reaction of 4a and acet-hydrazide according to this scheme, whereas 4a reacts with aromatic acid hydrazides 21c - e to give condensation products, which are presumably amidrazones 28. The 4,5-diaza-octatetraene derivative 30 results from the reaction of 4c with p-toluenesulfonylhydrazide. Ketene aminals 34a - c are the products of the reaction of the orthoamides 4b - d with 4,4-dimethylthiosemicarbazide 34, which cyclize on heating to give highmelting pyrazolethiones 35a - c. According to the crystal structure analysis of 35c the compounds have zwitterionic character and are associated via hydrogen bridges in the solid state.

Orthoamide, LV [1]. C7H7N3O6 - Tris(diformylamino)methan („Formylaalen“) - ein Orthoameisensäureamid-Derivat mit sechs Formylgruppen / Orthoam ides, LV [1]. C7H7N3O6 - Tris(diformylamino)methane ( “Formylaalen”) - an Orthoformic Acid Amide Derivative with Six Formyl Groups

Abstract The preparation of tris(diformylamino)methane (3), a hitherto unknown derivative of orthoformic acid, is described. In the presence of a Lewis acid the orthoamide 3 formylates activated aromatic compounds.