Reaktionen von Difluordichlormethan mit Kohlenwasserstoffen

Reactions of Difluoridichloromethane with Hydrocarbons The reaction of difluordichloromethane with different hydrocarbons between 150°C and 250°C yields the CFCl₂-substituted hydrocarbons. Beside it the corresponding chlorides are formed. For the hydrocarbons studied the following sequence of reactivity against difluordichloro-methane was found. n-paraffins < isoparaffins ≅ cycloparaffins < alkylaromatics < olefines.     

Reaktionen mit N-Acylimino-dithiokohlensäurediestern

Reactions with N-Acylimino-dithiocarbonic-acid-diesters . Reactions of N-acylimino-dithiocarbonic-acid-S,S-diesters 1 with nucleophilic com-pounds present new possibilities to synthesize heterocycles. With amines 1a reacts by mono- and disubstitution, respectively, of methylthio-groups to isothioureas 2 and guanidines 3 , with 1,2-bi-nucleophilic arenes to benzoheterocycles 4 , with aliphatic diamines to imidazolidines 5 , pyrimidines 6 , diazepines 7 and the hexamethylene-diamine-derivatives 8. 1a reacts also with hydrazines to 1,2,4-triazoles 9 and with hydrazides to the thiosemicarbazones 10 or 1,3,4-oxadiazoles 11 . Heterocyclisations of 1 with guanidines, thiourea, salts of thiourea and amidines give the 1,3,5-triazines 12, 14, 15 and 16 . N-benzoyl-dithiocarbonic-acid-methylester -amid reacts with CH-acidic compounds to thiazoles 17 . The structures of the final products are determined by i.r.-, ¹H-n.m.r.-, u.v.- and mass-spectras.     

Reaktionen einer technischen Butenfraktion mit Trichloracetaldehyd

Reactions of a Technical Fraction of Butene with Trichloroacetaldehyde In pyrolysis plants for gasoline production a C₄-fraction is formed containing isobutene, but-1-ene and but-2-ene as main products. The reactive separation of this fraction represents an industrial problem. One way to solve this problem is the reaction of trichloroacetaldehyde with these components to form addition products. The favoured reaction is the formation of 1,1,1-trichloro-4-methyl-pent-4-en-2-ol ( 1 ) and 1,1,1-trichloro-4-methyl-pent-3-en-2-ol ( 2 ) from iso-butene. The other isomers react very slowly. The influence of different reaction parameters was investigated to find a method for a reactive separation of the C₄-fraction.     

Reaktionen von 2,3-Dichlormaleinimiden mit methylenaktiven Verbindungen

Reactions of 2,3-Dichloromaleimides with Methyleneactive Compounds 2,3-Dichloromaleimides 1 react with activated methylene compounds mainly under monosubstitution to give 2–6 . Replacement of the second chloroatom gives 2,3-disubstituted maleimides 9–15 and stable ylides 16–27 with pyridine and triphenylphosphine, respectively. A general synthesis for such maleimid-ylides was found in a one-batch reaction from 2,3-dichloromaleimides 1 with methyleneactive compounds and pyridine or triphenylphosphine.     

Reaktionen von Acylketen-S,S-acetalen mit Aminen

Reactions of Acylketene S, S-acetals with Amines Reaction of acylketene S, S-acetals 1 with ammonia, aliphatic, and aromatic amines yields acylketene S, N-acetals 2 – 9 and acylketene N, N-acetals 12 , respectively. Acylketene S, N-acetals are further available by addition of isothiocyanates to substituted acetonitriles. The IR- and ¹H-NMR-spectra show that compounds 2 – 11 occur exclusively in the ketene S, N-acetal form. Reaction of 1 with ethylene diamine, ethanolamine and aromatic amines, respectively, which still have a nucleophilic substituent in ortho-position beside the amino group leads to the heterocycles 13 – 19 .     

Kinetische Untersuchungen der Reaktionen von Methylradikalen mit Allen

Kinetic Studies of the Reactions of Methyl Radicals with Allene The addition of methyl radicals to allene has been studied in the temperature range 573…595 K. The methyl radicals were produced by thermal decomposition of azomethane. It has been shown that the additions take place with a very high selectivity at the terminal carbon atoms in allene. The rate constant k₂ of the addition can be expressed by the following Arrhenius equation:      

Reaktionen mit Cyclobutendionen. LII. Reaktionen von 4-Hydroxy-3-phenyl-cyclobut-(3)-en-onen-(1) mit Arylhydrazinen

Reactions of Cyclobutendiones. LII. Reaction of 4-Hydroxy-3-phenyl-3-cyclobuten-1-ones with Arylhydrazines In the reaction of hydroxycyclobutenones of the typ 1 – 4 with arylhydrazines 5 an unexpected reaction behaviour is found. The major products are hydrazones of different structure, the well known hydroxy-cyclopropane-carboxylicacid hydrazines 6 [1] are byproducts. The direction of the reaction depends on the substituents X, on the different substituted arylhydrazines and the solvents.     

Reaktionen aromatischer Nitrile mit Dicarbonsäuredichloriden

Reactions of Aromatic Nitriles with Diacyl Dichlorides Dicarbonic acid dichlorides react with aromatic nitriles in the presence of SbCl₅ to give dicationic bis(1,3,5-oxadiazinium) salts 1. Reaction of 1 with ammonia or hydrazine yields derivatives of bis(1,3,5-triazine) ( 2 ) or bis(1,2,4-triazole) ( 3 ).     

Reaktionen von Malonsäureethylesteraniliden mit Heterokumulenen

Reactions of Malonanilic Acid Ethyl Esters with Heterocumulenes Malonanilic acid ethyl esters 1 react with carbon disulfide in the presence of sodium hydride to give disodium salts 2 . Treatment of 2 with an alkylation reagent yields the openchain or cyclic ketene S,S-acetals 3 and 4 , respectively. Adding only one equivalent of methyl iodide to 2 and acidifying the reaction mixture lead to the dithioesters 5 . Reaction of 3 with amines or o-amino-thiophenol yields S,N- and N,N-acetals only in some cases. S,N-acetals 6 are further available by addition of phenyl isothiocyanate to 1 whereas N,N-acetals are synthesized, too, by chlorination of 3 and reaction with amines. Acidifying of 11 gives the thioacetoanilides 12 . Some more reactions (oxidation of 3a , d and saponification/decarboxylation of 4a ) are discussed.