Zur Reaktivität monocyclischer α-Dinitrone

Reactivity of Monocyclic α-Dinitrones Syntheses of monocyclic α-dinitrones and their reactions with isocyanates are described.     

Zur Reaktivität von α-Hydroxyaldehyden,I Acetalbildung

Reactivity of α-Hydroxyaldehydes, I: Formation of Acetals α-Hydroxyaldehydes 1a – j obtained by hydrogenation of cyanohydrines do not yield uniform products when reacted with orthoformic ester. Beside ?normal”? acetals of type 2a – c cyclic products 3a – c with 1.4-dioxane structure are formed. On the other hand, reaction with propane-1.3-diol proceeds quantitatively to yield acetals of type 4a – j .     

Zum Reaktionsverhalten acylierter Carbamidsäureazide gegenüber Diazomethan

Reactions of N-Acyl-carbamic Azides with Diazomethane The reactions of N-thenoyl- and N-furoyl-carbamic azides were studied and the reactivity of N-acyl-carbamic azides towards diazomethane has been examined in different solvents.     

Synthese und Reaktivität des 3,5-Dinitrobenzoesäureanhydrids

Synthesis and Reactivity of 3,5-Dinitrobenzoic Anhydride 3,5-Dinitrobenzoic anhydride is available from 3,5-dinitrobenzoyl chloride by limited hydrolysis in THF/pyridine. The procedure is safe and provides excellent yields.     

Reaktionsfähigkeit von Glaucin gegenüber einigen halogenierenden Reagenzien

Reactivity of Glaucine Towards Some Halogenating Reagents 3-Chloroglaucine ( 2 ) was obtained when glaucine ( 1 ) was treated with chloramine T or PCl₅. Glaucine · HCl reacted with H₂O₂ to give 2 . The chlorination of 1 with AlCl₃ and H₂O₂ yielded a mixture of 2 , 3,8-dichloroglaucine ( 3 ) and 3,8,11-trichloroglaucine ( 4 ). Compound 4 was formed when 1 was treated with SO₂Cl₂. When heated with PCl₅, 1 gave a mixture of 2, 4 and 3,7-dichlorodehydroglaucine ( 5 ). 3-Bromoglaucine ( 6 ) was obtained from glaucine · HBr and H₂O₂. Treatment of 1 with N-bromosuccinimide yielded a mixture of dehydroglaucine ( 7 ) and 7-bromodehydroglaucine ( 8 ).     

Synthese von substituierten Indol-Derivaten, 2. Mitt. Zur Reaktivität eines cyclischen Chinon-Halbaminals

Synthesis of Substituted Indole Derivatives, II: The Reactivity of a Cyclic Quinonecarbinolamine The cyclic quinonecarbinolamine 1 reacts with basic nucleophiles to yield the indolemethylene derivatives 3 via an enol tautomer of 1 .     

Untersuchungen zur Reaktivität von Thiapseudophenalenonen und Thiapseudophenaleniumsalzen

Chemical Studies about the Reactivity of Thiapseudophenalenones and Thiapseudophenalenium Salts. The thiapseudophenalenone 1 can be alkylated by ?Meerwein-salt”? to give the thiapseudophenalenium salt 3 , which reacts with N-nucleophilic compounds (N-benzoyl- or 2,4-dinitrophenylhydrazine) to yield the hydrazones 4a and 4b . The reaction of 1 with the C-nucleophile 5 in acetic anhydride leads to the thiapseudophenafulvene derivative 6 . 6H-Anthra[1,9-bc]thiophenone ( 7 ) and triethyloxonium tetrafluoroborate form the cation 8 . With 2,4-dinitrophenylhydrazine in the presence of catalytic traces of H₃PO₄ compound 7 forms the hydrazone 9 .     

Reaktionsverhalten acylierter Isocyanate gegenüber Azomethinen

Reactions of Acyl-isocyanates with Azomethines The corresponding dihydro-1,3,5-oxdiazinones were obtained by reaction of N-acyl-isocyanates and azomethines, N-sulfonyl-triazinones by reaction of N-sulfonyl-isocyanates and azomethines.     

Darstellung und Reaktivität von α-Acyloxy-N-acylglycin-Derivaten

Synthesis and Reactivity of Derivatives of α-Acyloxy-N-acylglycine The N,O-Acylals 5–15 are obtainable from the chloro compounds 2 and carboxylic acids. Treatment of the electrophilic synthons with nucleophiles under basic conditions leads to products 16–19 by way of transamidoalkylation. A mechanism of the reaction is proposed.     

Darstellung,Reaktivität und spektroskopische Eigenschaften von Chlorformamidinen aus Quadratsäuredichlorid

Syntheses, Reactivities, and Spectroscopic Properties of Chloroformamidines from Squaric Acid Dichloride Reactions of carbodiimides with squaric acid dichloride ( 1 ) lead to chloroformamidines 6 which are hydrolyzed to yield ureas of type 7 or diarylureas and squaric acid.     

Zum Reaktionsverhalten von Pyryliumsalzen gegenüber basischen Reaktanten

Experiments on the Reactivity of Pyrylium Salts towards Basic Reactants The reactivity of some N-acyl-and N-sulfonyl-hydrazines 2 – 4 , 8 , 10a – 10g , 12 , 13 , 16a , 16b , and of hydrazones 18 , benzildihydrazone 21 towards pyrylium salts 1 was examined. By reaction of 2,4,6-trimethyl-pyrylium salt 1 with substituted hydrazines some pyridinium-salts were obtained. Relationships between basicity and reactivity were discussed.     

Ungesättigte und halogenierte γ-Hydroxysulfone; Darstellung und Reaktivität

Unsaturated and Halogenated γ-Hydroxysulfones: Syntheses and Reactivities α,β-Unsaturated γ-hydroxysulfones 2 and β-bromo-γ-hydroxysulfones 4 are prepared from the corresponding keto derivatives by reduction with dimethylaminoborane. Addition of p-toluenethiol to the double bond of 2 takes place in the position β to that of the sulfonyl group. With bases an isomerisation of 2 to γ-ketosulfones 10 is observed. With primary or secondary amines Mannich bases are formed. β-Bromo-γ-hydroxysulfones 4 are cleaved by bases to yield 2 .     

Heterokumulene und ihr Reaktionsverhalten gegenüber anderen Reaktanten II

The Reactivity of Heterocumulenes, II. The syntheses of new carbamidic esters 3 of 1,2-cyclohexanedione and of the new bicyclic 1,3,2-dioxaphospholene derivatives 9 and 10 are described. The reactivity of the bicyclic 1,3,2-dioxaphospholenes 11 towards N-sulfonylthionylimines 12 , acylated isocyanates 15 and phosphoryl isocyanates 18 and of the simple 1,3,2-dioxaphospholenes 25 towards diaryloxyphosphoryl isocyanates 26 was studied. The new heterocyclic systems 13, 16, 19, 24 and 27 were obtained. The structures of these substances and their spectroscopic properties are reported.     

Heterokumulene und ihr Reaktionsverhalten gegenüber anderen Reaktanten I

The Reactivity of Heterocumulenes, I. The reactivity of phenyl isothicyanate towards benzyne was investigated. The structure of the reaction products 3 – 8 were clarified, the unknown N-phosphoryl- and N-thiophosphorylcarbamidic azides 11 – 11c and 13 wird carbamoyltriphenylphosphoranes 16a–16i were isolated.     

Photochemische Reaktivität von 5-Desazaflaviniumsalzen und 5-Desazaflavinen – ein Vergleich

Photochemical Reactivities of 5-Deazaflavinium Salts and 5-Deazaflavins The photochemical reactivities of the title compounds 3 are compared with those of 5-deazaflavins. Both groups of compounds behave similar, but the flavin analogy is rather limited with compounds of type 3a . They behave more like analogues of nicotinamide.     

Das Reaktionsverhalten acylierter Heterokumulene gegenüber Phospholenen, 2. Mitt

The Reactivity of N-Acyl-heterocumulenes towards Phospholenes, II The reactivity of N-sulfonyl-isocyanates 1 towards the phospholenes 2 and of 1 and N-sulfonylisothiocyanates towards substituted dihydro-1,3,4,2-oxadiazaphospholenes 9 was examined; by reaction of N-acyl-isocyanates 18 and phospholenes 17 the 5-N-acyl-oxazolinones 19 were obtained.     

Das Reaktionsverhalten acylierter Heterokumulene gegenüber Phospholenen, 3. Mitt

The Reactivity of N-Acyl-heterocumulenes towards Phospholenes, III The reactivity of oxa-diaza-phospholenes 7 towards the N-acyl-isocyanates 8 and N-acyl-isothiocyanates 9 , of 12 and 16 towards carbon disulfide ( 13 ) and of 18 and 22 towards the substituted N-sulfonyl-isocyanates 19 and 23 was examined and the structures of the obtained products determined.