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Showing papers on "Diazomethane published in 1970"


Journal ArticleDOI
TL;DR: Ketene and diazomethane flash photolytic measurement of reaction rates of singlet-triplet methylene deactivation was carried out in this article, where the reaction rates were shown as a function of the number of methylene atoms.
Abstract: Ketene and diazomethane flash photolytic measurement of reaction rates of singlet-triplet methylene deactivation

194 citations


Journal ArticleDOI
TL;DR: In this article, Diazomethane reacts with organoditellurides, diselenides, and disulfides to give telluro-, seleno-, and thioacetals.
Abstract: Die Umsetzung von Diazomethan mit einigen Ditelluriden, Diseleniden und Disulfiden ergibt die entsprechenden Tellur-, Selen - und Thioacetale. Mechanismen fur diese Umsetzungen werden vorgeschlagen. Reaction of some Ditellurides, Diselenides, and Disulfides with Diazomethane Diazomethane reacts with organoditellurides, -diselenides, and -disulfides to give telluro-, seleno-, and thioacetals. Mechanisms for this reaction are suggested.

51 citations


Journal ArticleDOI
TL;DR: The structure of pyrazole-3(5)-diazonium chloride with an equimolar amount of diazomethane is described in this article, where it is shown that pyrazol reacts with Na-azide to give the hitherto unknown 3 (5)-azido-pyrazole.
Abstract: 3(5)-[Tetrazolyl-(l)]-pyrazol (2) und Pyrazolo[5.l-c]triazol (3) entstehen bei aquimolarer Umsetzung von Pyrazol-3(5)-diazoniumchlorid (1) mit Diazomethan. Bei zweifachem Uberschus an Diazomethan isoliert man neben 2 die isomeren N-Methyl-Derivate 10 und 11. Die Strukturen wurden auf Grund spektroskopischer Daten zugeordnet. Die Addition von Propiolsaureester an Diazo-cyclopentadien fuhrt zu einem blauen 2(1)H-Cyclopenta[c]pyridazin, das mit Azulen isoelektronisch ist. 1 reagiert mit Na-Azid zum noch unbekannten 3(5)-Azido-pyrazol. Reactions of 3(5)-Diazopyrazole, IV. 3(5)-(l-Tetrazolyl)pyrazole (2) and pyrazolo[5,1-c]triazole (3) are obtained by the reaction of pyrazole-3(5)-diazonium chloride (1) with an equimolar amount of diazomethane. With a twofold excess of diazomethane the two isomeric N-methyl derivatives 10 and 11 are isolated in addition to 2. The structures are based on spectroscopic data. The addition of methyl propiolate to diazocyclopentadiene leads to a blue 2(l)H-cyclopenta[c]pyridazine isoelectronic with azulene. 1 reacts with Na-azide to give the hitherto unknown 3(5)-azido-pyrazole.

43 citations


Journal ArticleDOI
TL;DR: In this article, C-and O-D-glucopyranosides were treated with diazomethane in methanol or in methenol-dimethylformamide mixture to give a mixture of methyl ethers, in which 3-methyl ether is the major.
Abstract: On treatment of some C-and O-D-glucopyranosides with diazomethane in methanol or in methanol-dimethylformamide mixture, a partial methylation of the sugar moiety took place, though to a slight extent, to give a mixture of methyl ethers, in which 3-methyl ether is the major. The reaction is much favored in the presence of a small amount of stannous chloride. A O-α-D-glucopyranoside gave almost exclusively the corresponding 3-methyl ether of the glucose residue, while the β-anomer provided, beside 3-methyl ether, 2, 3-dimethyl ether nearly in equal amount. The benzylidene derivatives of O-α-and β-D-glucosides gave also the corresponding 3-methyl ether but 2, 3-dimethyl ether was formed only in trace and, instead, 2-methyl ether was provided.

34 citations


Journal ArticleDOI
TL;DR: In this article, 3-Arylisoxazol-5-ones and 5-arylisoxozol-3-ones were prepared and converted to the N-methyl and O-methyl derivatives by reaction with diazomethane.
Abstract: 3-Arylisoxazol-5-ones and 5-arylisoxazol-3-ones were prepared and converted to the N-methyl and O-methyl derivatives by reaction with diazomethane. The halogen in 3-phenyl-5-chloroisoxazole was rep...

33 citations


Journal ArticleDOI
TL;DR: In this paper, a 3.3,3-trimethyl-2-methylene-indoline (Fischer base) was shown to react with arylsulfonyl azides to give diazomethane (81-87%).

29 citations


Journal ArticleDOI
TL;DR: A number of nonamino organic acids associated with inborn errors of metabolism can be detected by gas chromatography and Chromatographic patterns for normal and abnormal urines have been established.
Abstract: A number of nonamino organic acids associated with inborn errors of metabolism can be detected by gas chromatography. The organic acids are extracted into ethyl acetate and diethyl ether, the extracts combined, and the solvents evaporated under nitrogen. The residue is taken up in carbon disulfide and an aliquot chromatographed on 5% neopentyl glycol adipate to separate short-chain fatty acids (C 2 to 6). The remaining carbon disulfide is evaporated, the residue taken up in methanol, and the acids are methylated with diazomethane. The solvent is evaporated, the residue taken up in tetrahydrofuran, and an aliquot chromatographed on 15% diethylene glycol succinate to separate keto, hydroxy, and dicarboxylic acids. Chromatographic patterns for normal and abnormal urines have been established. Four cases of congenital methylmalonic aciduria have been diagnosed by this procedure.

27 citations



Journal ArticleDOI
TL;DR: In this paper, the absence of basophilia of acid mucosubstances after a so-called histochemical methylation with acidified methanol may be due to the lactonisation of carboxyl groups rather than, as is generally held, their esterification.
Abstract: The results reported in this paper substantiate Vilter's (1968) hypothesis that the absence of basophilia of acid mucosubstances after a so-called histochemical methylation with acidified methanol may be due to, among other factors, the lactonisation of carboxyl groups rather than, as is generally held, their esterification. Sections from several fixed tissues of Syrian hamster and mouse were treated at 60 ° or at room temperature with dry methanol, ethanol, butan-l-ol, benzene or cyclohexane containing 0.35% hydrogen chloride or 1% thionyl chloride. Others were treated with methanolic methyl iodide or etheral diazomethane. With most of these solutions, the azurophilia attributable to mucosubstance carboxyl and sulphate half-ester groups was eventually abolished; subsequent saponification restored only the azurophilia due to carboxyl groups. However, some variation was found for each “methylating” agent, and also between different mucosubstances.

24 citations


Journal ArticleDOI
TL;DR: In this article, the mode of reaction of diazomethane, diazoethane and 1-diazopropane with methylene cyclopropenes 8 and 15 is investigated.
Abstract: Die Umsetzungen von Diazomethan, Diazoathan und 1-Diazo-propan mit den Methylen-cyclopropenen 8 und 15 werden untersucht. 8 ergibt Pyridazin-Derivate, im Falle des Diazoathans wird als Zwischenstufe die cyclische Azoverbindung 12 gefast. 15 liefert Pyrazolenin Derivate, die thermisch zum Pyrazol 20 bzw. Den Cyclopropenen 17 a und b umgewandelt werden. Die Reaktionsmechanismen werden diskutiert. On the Mode of Reaction of Methylene Cyclopropenes with Diazo Alkanes The reactions of diazomethane, diazoethane and 1-diazopropane with methylene cyclopropenes 8 and 15 are investigated. 8 yields pyridazine derivatives; with diazoethane the cyclic azo compound 12 is obtained as an intermediate of pyridazine formation. 15 yields pyrazolenine derivatives which are transformed thermally either to pyrazole 20 or to the cyclopropene derivatives 17a and b. The reaction mechanisms are discussed.

19 citations




Journal ArticleDOI
TL;DR: The synthesis and characterisation of the Group IVB organometallic diazomethanes is described in this article, where the compounds are volatile, nonexplosive, photosensitive, and reactive.
Abstract: The synthesis and characterisation of the Group IVB organometallic diazomethanes is described. The compounds prepared were Me3Si·CHN2, (Me3M)2CN2(M = Ge, Sn, or Pb), Me3Si(Me3Sn)CN2, (Ph3Ge)2, and (R3Sn)2CN2(R = Et, Bun, or Ph). Two preparative methods have been explored: from diazomethane and the metal amide R3M·NMe2, and from diazomethyl-lithium and the appropriate chloride; their scope and limitation is discussed. The compounds are volatile, non-explosive, photosensitive, and reactive. Six Sn–C cleavage reactions of (Me3Sn)2CN2 are described; nitrogen is generally lost and the carbene (Me3Sn)2C: may be an intermediate.


Journal ArticleDOI
TL;DR: In this paper, the synthesis of dipeptide derivatives of 3.3.3-trifluoroalanine and its use for Peptide Syntheses is described.
Abstract: Aus 3.3.3-Trifluor-alanin (1) werden verschiedene N-Acyl-Derivate und Ester dargestellt. Ungewohnlich ist die Bildung eines kristallinen Dicyclohexylammonium-Salzes und die Veresterung zu 2 mit atherischem Diazomethan. Mit Basen tritt leicht Eliminierung von HF ein. Die Synthese von Dipeptid-Derivaten, die 1 enthalten, wird beschrieben. Fluoro Amino Acids, V. Reactions of 3.3.3-Trifluoroalanine and its Use for Peptide Syntheses N-Acyl derivatives and esters of 3.3.3-trifluoroalanine (1) are prepared. The formation of a cristalline dicyclohexylammonium salt and esterification with diazomethane/ether to give 2 are unusual. With bases an easily occurring elimination of HF is observed. The synthesis of dipeptide derivatives of 1 is described.


Journal ArticleDOI
TL;DR: The Mannich reaction on 3-oxo-5,6-diphenyl-2,3-dihydro-1,2,4-triazine (1) and on 3,5-dioxo-6-phenyl, 2,3,4,5,tetrahydro, 1.4, and 3.4 triazin (4) using piperidine or morpholine together with formaldehyde, leads to the formation of 5a, b and 6a, respectively, b, respectively.


Journal ArticleDOI
TL;DR: In this article, the synthesis and reaction of benzoxadiazines with Diazomethane was investigated. But the results were limited to the tautomeric 1H-4,1,2,1.2-benzoxaddiazines.
Abstract: o-Chinondiazide werden mit Diazomethan zu 3 H-4.1.2-Benzoxadiazinen (1) umgesetzt, deren Umlagerung zu den tautomeren 1H-4.1.2-Benzoxadiazinen (2) untersucht wird. 1 addiert Diphenylketen unter Bildung eines neuen Vierringsystems (3). Durch selektive Reduktion von 1 wird eine gemischt aromatisch-aliphatische Azoverbindung (4 a) erhalten. Reactions with Diazocarbony1 Compounds, XXXV Synthesis and Reactions of Benzoxadiazines o-Quinone diazides react with diazomethane to form 3H-4,1,2-benzoxadiazines (1), the rearrangement of which to the tautomeric 1H-4,1,2-benzoxadiazines (2) has been investigated, 1 adds diphenylketene to yield a new four ring system (3). By selective reduction of 1 a mixed aromatic-aliphatic azo compound (4a) is obtained.

Journal ArticleDOI
TL;DR: In this article, a mixture of carboxylic acid and dicyclohexyl carbodi-imide was used to obtain 4-diazo-3-oxobutane-1-carbonitrile.
Abstract: The addition of a mixture of a carboxylic acid (1 mol.) and dicyclohexylcarbodi-imide (1 mol.) in ether to diazomethane (1·25 mol.) or diazoethane (1·25 mol.) provides the corresponding diazo-ketone (ca. 0·5 mol.) through an acid anhydride intermediate. This procedure is useful for the preparation of diazo-ketones which cannot be prepared by conventional procedures from the acid chloride; e.g., attempts to prepare 3-cyanopropionyl chloride have been unsuccessful but the addition of diazomethane to a mixture of 3-cyanopropionic acid and dicyclohexylcarbodi-imide gave 4-diazo-3-oxobutane-1-carbonitrile in ca. 30% yield.


Journal ArticleDOI
TL;DR: In this article, a technique that permits esterification with diazomethane and rapid extraction in a single step is described, and the technique is shown to work well in a variety of applications.
Abstract: Briefly describes a technique that permits esterification with diazomethane and rapid extraction in a single step.

Journal ArticleDOI
TL;DR: In this paper, a number of uramils and 5-aryldialuric acids from o-substituted anilines are described, and their precursors are described.
Abstract: Preparation of a number of uramils and 5-aryldialuric acids from o-substituted anilines is described. Methylation of the uramils gave dimethoxy-N-monomethyl pyrimidine derivatives accompanied by minor amounts of trimethoxy-pyrimidines, and the dialuric acids gave 1,3-dimethylpyrimidines or 5-methoxy-1,3-dimethylbarbituric acids (with an excess of diazomethane). Ring contraction of the 1,3-dimethyldialuric acids gave the isomeric 5-N-methylcarbamoyloxazolidine-2,4-diones. The dialuric acid from dimedone gave a trimethyl derivative (a methoxycyclohexenyl-1,3-dimethyldialuric acid). Anthranilic acid and alloxan in acetic acid gave a benzoxazonespirobarbituric acid, but in aqueous ethanol yielded a dialuric acid which was characterized by conversion into several derivatives. Infrared and N.M.R. data are recorded for the uramils, dialuric acids, and their derivatives.

Journal ArticleDOI
TL;DR: In this article, a general method for the synthesis of several compounds containing the essential neobetanidine chromophore (a 1, 7diazaheptamethine system incorporating a pyridine ring) consisted of Vilsmeier-Haack condensations involving the active (enolizable) methyl group of γ-picoline.
Abstract: The total synthesis of a neobetanidine derivative (3b) is described. Preliminary experiments led to the synthesis of neobetenamine (4), which presents the ring system of neobetanidine (3). A general method for the synthesis of several compounds containing the essential neobetanidine chromophore (a 1, 7-diazaheptamethine system incorporating a pyridine ring) consisted of Vilsmeier-Haack condensations involving the active (enolizable) methyl group of γ-picoline. Neobetenamine (4) resulted from this reaction with N-formyl-indoline, and also by an amine exchange between indoline and the Vilsmeier-Haack product from γ-picoline and N-methyl-formanilide. The methyl group of γ-picoline-2, 6-dicarboxylic ester 9, however, was resistant to the Vilsmeier-Haack condensation, but could be activated by introduction of a carboxyl into it: 4-chloropyridine-2, 6-dicarboxylic ester (11a) (from chelidamic ester) was used to alkylate malonic ester. The product (12a) lost only one carboxyl group when saponified. The resulting 2, 6-dicarboxy-pyridine-4-acetic acid (13a) readily underwent a novel decarboxylative condensation with the Meerwein acetal of dimethyl formamide to 4-(2-dimethylamino-vinyl)-2, 6-dimethoxycarbonyl-pyridine (14b), the first synthetic derivative of a neobetalaine. The enamine 14b was subjected to amine exchange reactions with indoline to 2-decarboxy-5, 6-dideoxy-neobetanidine dimethyl ester (15), and with (S)-cyclodopa (16) 5, 6-di-O-methyl-neobetanidine trimethyl ester (3b). The latter was identical with the diazomethane transformation product of betanidine (1), the aglucone of the pigment of the red beet, betanine. A few proton resonance and electron spectral properties, as well as the basicities of several of the synthesized compounds, are tabulated and discussed as far as they express special structural and electronic features of the common 1, 7-diazaheptamethine chromophore.


Journal ArticleDOI
TL;DR: Column chromatography of an extract of the lichen Ramalina stenospora is described in this article. But it is not known whether the extract is derived from stenosporic acid with diazomethane.

Journal ArticleDOI
TL;DR: In this paper, the acids named in the title were synthesised from pyrroles containing carboxy- or ester groups and N-methylated by diazomethane.
Abstract: The acids named in the title were synthesised. In the case of pyrroles already containing an ester group, a carboxylic function can be introduced by use of phosgene, but better by use of oxalyl chloride; and acetic ester group can be introduced by use of diazoacetic ester. Some pyrroles containing carboxy- or ester groups are N-methylated by diazomethane.

Journal ArticleDOI
TL;DR: Bis(trifluoromethyl)diazomethane (1) reacts with the compounds (CH3)3MC≡CCF3 (M = Ge, Sn) to give the cyclopropenes as discussed by the authors.
Abstract: Bis(trifluoromethyl)diazomethane (1) reacts with the compounds (CH3)3MC≡CCF3 (M = Ge, Sn) to give the cyclopropenes . Cyclopropenes are also obtained from the reaction of 1 with the acetylenes RC≡C...


Journal ArticleDOI
TL;DR: In this paper, it was shown that the direct methylation of 3-acetyl-5,7-dimethylcoumarin can be traced to a transition state having the shape of a pyrazoline.
Abstract: Diazomethane rapidly converts 3-acetylcoumarin, 3-cyanocoumarin, and their derivatives into the related 4-methyl-coumarins. Since an acetyl group must rotate out of the plane of conjugation to allow the methyl group to enter, it is a less effective activating substituent than cyanide in alkylation reactions.Substituents at the 5-position interfere with the methylation process so that 3-acetyl-5,7-dimethylcoumarin adds diazomethane giving a pyrazoline derivative (XIII) in the usual way. Methanol converts this pyrazoline into oxepin lactones, e.g. 3-acetyl-4,5-dihydro-4-methoxy-6,8-dimethyl-1-benzoxepin-2(3H)-one (XVIII). Thermolysis of the pyrazoline is unusual in regenerating some of the coumarin from which it was made; the main product, however, is a labile substance giving 3-acetyl-6,8-dimethyl-1-benzoxepin-2(3H)-one (XVII) when isolation was attemptedAt –40° diazomethane and 3-acetyl-5,6-benzocoumarin give 1,11c-dihydro-3a-(2-methyloxiranyl)benzo-[5,6]chromeno[3,4-c]pyrazol-4(3aH)-one (XXIV), but at 0° the sole isolable product is 8a-acetyl-11a,12-dihydro-11H-naphtho[1′,2′:6,7]oxepino[3,4-c]pyrazol-8(8aH)-one (XXII).These results support the view that the ‘direct’ methylation begins with an intermediate or transition state having the shape of a pyrazoline but at least one bond which is as much ionic as covalent in character. It continues with hydrogen migration because this restores the delocalisation energy of the coumarin system lost during the addition. The arguments also clarify some of the reasons for cyclopropane ring formation in certain related series.