Thermal Isomerization of 2-Bromo-2-fluoro-1-alkylidenecyclopropanes in Polar Solvents

2-Bromo-2-fluoro-1-alkylidenecyclopropanes heated in polar solvents undergo isomerization into substituted 3-bromo-2-fluoro-1,3-butadienes. 2-Bromo-3-methyl-1-methylene-3-phenyl-2-fluorocyclopropane at heating afforded a mixture of substituted 1-(bromofluoromethylene)cyclopropane and isomeric 1-bromo-1-fluoro-1,3-butadienes.     

Synthesis and Photochemical Behaviour of 2-Amino-1,3-Cyclohexadienes

The reaction of the 4,4-dialkylated 2-cyclohexenones 1 or 2 with a twofold excess of a secondary amine 3 affords the 2-amino-1,3-cyclohexadienes 4 and 5 , respectively. Irradiation (λ ≧ 300 nm) of the morpholino derivative 4a yields a mixture of the isomeric 3-morpholino-6-methyl-1,3,5-heptatrienes 6 and 7 , while 5 gives only one corresponding product 8 . The reaction of enone 1 with an equimolar amount of pyrrolidine ( 3c ) affords the bis-enamine 9 which is converted to the unsaturated diketone 10 by oxidative hydrolysis.     

Reactions of 2-Amino-4-methyl-6-(2-pyridyl)- and 2-Amino-4-methyl-6-phenyl-7,8-dihydroindazolo[4,5-d]thiazoles with Aldehydes

The reaction of 2-amino-4-methyl-6-(2-pyridyl)-7,8-dihydroindazolo[4,5-d]thiazole, obtained by treating 3-methyl-4-oxo-1-(2-pyridyl)-4,5,6,7-tetrahydroindazole with pyridinium bromide perbromide and then with thiourea, and 2-amino-4-methyl-6-phenyl-7,8-dihydroindazolo[4,5-d]thiazole with 4-bromo-, 4-fluoro-, 4-dimethylamino-, 4-methoxy-, 3,4-dimethoxy-, and 3,4-methylenedioxybenzaldehydes, furfural, pyridinecarbaldehyde, and thiophenecarbaldehyde gave the corresponding Schiff bases. The products of the condensation of these aminothiazoles with cinnamaldehyde, 1-(2-pyridyl)- and 4-chloro-1-(2,4-difluorophenyl)-5-formyl-3-methyl-6,7-dihydroindazoles, 2-formyl-dimedone, and 2-formyl-1,3-indanedione were also obtained.     

Synthesis of N-Substituted Derivatives of 2-(4-Amino-2-methyl-1H-indol-3-yl)- and 2-(6-Amino-2-methyl-1H-indol-3-yl)acetic Acids

A method was developed for the production of indole compounds containing an amino group at positions 4 and 6 of the benzene ring on the basis of the indolization of the 3-acetylaminophenylhydrazone of ethyl levulinate. A series of derivatives of 2-(4-amino-2-methyl-1H-indol-3-yl)- and 2-(6-amino-2-methyl-1H-indol-3-yl)acetic acids at the 4- and 6-amino group were synthesized.     

Alkylation of 1-alkoxy-3-methyl-1-triazene 2-oxide sodium salts

1-Alkoxy-3-methyl-1-triazene 2-oxide sodium salts react with chloromethyl methyl sulfide to give a mixture of 1-alkoxy-3-methyl-3-(methylthiomethyl)-1-triazene 2-oxides and 3-alkoxy-1-methyl-3-(methylthiomethyl)-1-triazene 2-oxides. The reaction of these triazene oxide sodium salts with 3,3-dialkyl-1-chloromethoxy-1-triazene 2-oxides produces a complex mixture of product bearing the oxytriazene moieties of the starting alkoxy-1-triazene 2-oxides bonded with the methylene group as a key structural fragment.     

Energetic characterization of indanone derivatives involved in biomass degradation

Journal of Thermal Analysis and Calorimetry - The energetic study of 6-methyl-1-indanone, 6-methoxy-1-indanone and 5,6-dimethoxy-1-indanone has been developed using calorimetric techniques and a...     

Researches on 2, 1, 3-thia- and selenadiazole

Depending on the reaction conditions, benzo-2, 1, 3-selenadiazole (I), dichlorodimethyl ether and aluminum chloride react to give a complex IV, or else 4-chloromethyl-(V) or 4, 7-di(chloromethyl) benzo-2, 1, 3-selenadiazole (VI). 5-(II) and 4-methylbenzo-2,l,3-selenadiazole(III) are chloromethylated by dichlorodimethyl ether in the presence of chlorosulfonic acid. Compound II is converted mainly into 5-methyl-4-chloromethylbenzo-2, 1, 3-selenadiazole(VII) or a mixture of three possible isomers VII, VIII, and IX, depending on the amount of base or pseudo-base in the reaction mixture. Ill gives mainly 4-methyl-7-chlorornethylbenzo-2, 1, 3-selenadiazole(X), independent of the presence of base. The structures of the chloromethylation products are shown by reductive splitting to o-diamides, and chromatography of the latter in the presence of reference spots. The high reactivity of the chlorine in the chloromethyl group made it possible to obtain new derivatives by replacing it with a hydroxyl, cyano, or thiocyano group.For Part XL see [1].     

Addition-Rearrangement of Aryl- and Alkoxysulfonyl Isocyanates with 5-Methyl-Substituted 3,4-Dihydro-2-methoxy-2H-pyrans. Selective Synthesis of Functionalized 2-Piperidones(1)

3,4-Dihydro-2-methoxy-5-methyl-2H-pyran and 3,4-dihydro-2-methoxy-5,6-dimethyl-2H-pyran undergo addition-rearrangement reactions with arylsulfonyl isocyanates to generate the corresponding 3-formyl- and 3-acetyl-6-methoxy-3-methyl-1-(arylsulfonyl)-2-piperidones. For example, 3,4-dihydro-2-methoxy-5-methyl-2H-pyran and phenylsulfonyl isocyanate afforded 3-formyl-6-methoxy-3-methyl-1-(phenylsulfonyl)-2-piperidone as a separable trans/cis mixture in high yield. The more reactive phenoxysulfonyl and alkoxysulfonyl isocyanates provided analogous results.     

Synthesis and methylation products of 4(5)-(2-furyl)imidazole

Bromination of 2-acetylfuran with copper(II) bromide in a mixture of ethyl acetate and chloroform leads selectively to furacyl bromide, the nucleophilic substitution of bromine in which by OAc and subsequent use of the Weidenhagen reaction enabled the synthesis of 4(5)-(2-furyl)imidazole. On N-methylation of this imidazole in KOH–acetone 2 isomers are formed, the 1-methyl-4- and 1-methyl-5-(2-furyl)imidazoles. It was established that, unlike alkylation of 4(5)-phenylimidazole, the main product of the reaction is 1-methyl-5-(2-furyl)imidazole.     

Nitroimidazoles. V . Synthesis of 1-methyl-2-(2-methyl-4-thiazolyl)nitroimidazoles

Reaction of readily available 2-methyl-4-formylthiazole ( 1 ) with glyoxal and ammonia gave 2-(2-methyl-4-thiazolyl)imidazole ( 2 ). Nitration of 2 with a mixture of nitric acid-sulfuric acid at 100° yielded 2-(2-methyl-4-thiazolyl)-4,5-dinitroimidazole ( 3 ) as the sole reaction product, while nitration at 65° afforded 2-(2-methyl-4-thiazolyl)-4-(or 5)-nitroimidazole ( 4 ). N-Methylation of compound 4 in the presence of base gave 1-methyl-2-(2-methyl-4-thiazolyl)4-nitroimidazole ( 6 ), whereas N-methylation with diazomethane afforded 1-methyl-2-(2-methyl-4-thiazolyl)-5-nitroimidazole ( 5 ). N-Methylation of compound 3 yielded 1-methyl-2-(2-methyl-4-thiazolyl)-3,5-dinitroimidazole ( 7 ) in high yield.     

Transformations of 2-(3-Hydroxy-3-methyl-1-butynyl)adamantan-2-ol >Catalyzed by Acids

Reaction of 2-(3-hydroxy-3-methyl-1-butynyl)adamantan-2-ol with acetonitrile under Ritter reaction conditions is accompanied by isomerization and partial hydration where the water addition to the triple bond occurs nonselectively. As a result of reaction carried out in the presence of 8 equiv of sulfuric acid a mixture was obtained of N ²-[4-(1-acetylamino-2-adamantyl)-2-methyl-3-butyn-2-yl]acetamide, N ³-[1-(1-acetylamino-2-adamantyl)-3-methyl-2-oxo-3-butyl]-acetamide, and N ³-[1-(1-acetylamino-2-adamantyl)-3-methyl-1-oxo-3-butyl]acetamide in ~10:3:2 ratio. In the presence of 2 equiv of the acid the mixture obtained consisted of N ²-[4-(1-acetylamino-2-adamantyl)-2-methyl-3-butyn-2-yl]acetamide, N ³-[1-(1-acetylamino-2-adamantyl)-3-methyl-2-oxo-3-butyl]acetamide, and 1-(1-acetylamino-2-adamantyl)-3-methyl-2-buten-1-one in the same ratio. In Rupe reaction conditions we obtained instead of the expected ,-unsaturated ketones a mixture of 1-(1-hydroxy-2-adamantyl)-3-hydroxy-3-methylbutan-1-one and 1-(1-hydroxy-2-adamantyl)-3-hydroxy-3-methylbutan-2-one in a 5:3 ratio.     

Formation of pyrrole derivatives through aminolysis of 2-azetidinone derivatives

A mixture of 3-(α,β-epoxyisopropyl)-1-phenyl-2-azetidinone and benzylamine was heated in a sealed tube at 120–130° yielding 4-anilinomethyl-1-benzyl-3-hydroxy-3-methyl-2-pyrrolidinone as a mixture of diastereoisomers. By this method, 4-anilinomethyl-3-hydroxy-3-methyl-1-phenyl-2-pyrrolidinone and 4-anilinomethyl-3-hydroxy-3-methyl-1-(3,4-dimethoxyphenethyl)-2-pyrrolidinone were obtained by using aniline and 3,4-dimethoxyphenethylamine, respectively, instead of benzylamine. The reaction of 4-formyl-1-phenyl-2-azetidinone with 3,4-dimethoxyphenethylamine afforded 4-anilino-1-(3,4-dimethoxyphenethyl)-2,3-dihydro-2-oxopyrrole. In a similar fashion, the 1-n-butyl and 1-isobutyl analogues were obtained by the use of n-butylamine and isobutylamine, respectively, instead of 3,4-dimethoxyphenethylamine.     

On the Mechanism of Condensation between 5—Amino—4,6—dichloro—2—methylpyrimidine and 1—Acetyl—2—imidazolin—2—one

The condensation reaction between 5-amino-4,6-dichloro-2-methylprimidine and 1-acetyl-2-imidazolin-2-one using POCl3 as solvent gave 4,6-dichloro-2-methyl-5-(1-acetyl-tetra-hydro-imidazo-2-ylidene)-aminopyrimidine predominantly and 4,6-dichloro-2-methyl-5-{1-1-(2-oxo-tetrahydro-imidazolyl)]-acetene}-aminopyrimidine as by-product. No 4,6-dichloro-2-methyl-5-(1-acetyl-2-imidazolin-2-yl)-aminopyrimidine was found. The result indicated an esterifi-cation-addition-elimination mechanism.     

2-Amino-2-thiazoline. V. phenylthioureido and phenylureido derivatives of 2-thiazoline

The reaction of 2-amino-2-thiazoline (I) with phenylisothiocyanate has been reported to give 2-imino-3-phenylthiocarbamoylthiazolidine (II) at low temperatures and l-phenyl-3-(2-thiazolin-2-yl)-2-thiourea (III) at ca. 100°. When performed by us, however, this reaction gave only a single mono-adduct regardless of the temperature. Nmr and chemical evidence indicates that structure III is the correct one. Treatment of I with phenylisocyanate also gave a mono-adduct which was established to be l-phenyl-3-(2-thiazolin-2-yl)urea (V). Compound I does not form a simple di-adduct with excess phenylisothiocyanate but does so with phenylisocyanate to give 2-phenylcarbamoylimino-3-phenylcarbamoylthiazolidine (VI). The reaction of III with phenylisocyanate gives 2-phenylthiocarbamoylimino-3-phenylcarbamoylthiazolidine (VII), however, the corresponding reaction of V with phenylisothiocyanate does not give the anticipated product but a mixture of compounds which includes VI and VII.     

Synthese von bromosubstituierten Butenoliden II

Synthesis of Bromosubstituted Butenolides II . Methyl 4,4′-dibromosenecioate ( 2 ) was prepared by double N-bromosuccinimide bromination of methyl senecioate ( 1 ) and converted to methyl 4,4′-diiodo-senecioate ( 3 ) with sodium iodide and to 3-bromomethyl-2-buten-4-olide ( 4 ) with aqueous hydrobromic acid. A mixture of methyl (Z)- and (E)-4-bromosenecioate ( 8 and 9 ) yielded 3-methyl-2-butenolide ( 5 ) with aqueous hydrobromic acid and a mixture of (Z)-and (E)-4-methoxy-senecioic acid ( 10 and 11 ) with methanolic potassium hydroxide. N-Bromosuccinimide treatment of the butenolide 5 afforded 4-bromo-3-methyl-2-buten-4-olide ( 6 ) and 4,4-dibromo-3-methyl-2-buten-4-olide ( 7 ).     

Azabicyclo chemistry II. Synthesis of 1,5-methano-2,3,4,5-tetrahydro-1H-2-benzazepines. B-norbenzomorphans

The syntheses of the B-norbenzomorphans, 1,5-methano-2,3,4,5-tetrahydro-1H-2-benzazepine (1a) and its N-methyl derivative (Ib) were accomplished. Phenylsuccinic anhydride (III) was cyclized to 3-carboxy-1-indanone (IVa), which was converted by the Arndt-Eistert method to the homologous methyl indanone-3-acetate (V). One experiment in the synthesis of V led to the by-products 3-carboxamido-1-indanone (IVd) and 3-(N-methylcarboxamido)-1-indanone (IVe), identified by physical and chemical means. Methyl 1-aminoindan-3-acetate (VII) was prepared by catalytic reduction of methyl indanone-3-acetate oxime (VI). Hydrolysis of VII afforded 1-aminoindan-3-acetic acid (VIII), which was cyclized with dicyclohexylcarbodiimide to 1,5-methano-2,3,4,5-tetrahydro-1H-2-benzazepin-3-one (IX). Reduction (lithium aluminum hydride) of IX gave amine Ia which was then methylated to Ib. The mass spectral fragmentation patterns of IX and Ia are discussed.     

Nitration of 2- and 4-[2-(2-furyl)vinyl]thiazole derivatives

Nitration of 4-methyl-2-[2-(nitro-2-furyl)vinyl]thiazole with a mixture of concentrated nitric and sulfuric acids leads to 4-methyl-5-nitro-2-[2-(3,5-dinitro-2-furyl)vinyl]thiazole. Under the same conditions 2-methyl- and 2-acetamido-4-[1-R-2-(5-nitro-2-furyl)vinyl]thiazoles (R=CH₃, Cl) are nitrated in the 3 position of the furan ring, 2-amino-4-[1-chloro-2-(5-nitro-2-furyl)vinyl]thiazole is nitrated in the 5 position of the thiazole ring and 2-acetamido-5-nitro-4-[2-(2-furyl)vinyl]thiazole undergoes profound changes. Under the influence of a mixture of of nitric acid and acetic anhydride the latter compound is converted quantitatively to the 5-nitro derivative (with respect to the furan ring), whereas 4-[2-(5-nitro-2-furyl)vinyl]thiazole derivatives do not undergo reaction.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 314–317, March, 1977.     

Regioselective conversion of 3-cyano-6-hydroxy-2-pyridones into 3-cyano-6-amino-2-pyridones

The reaction of a tautomeric mixture of 1-butyl-1,2-dihydro-6-hydroxy-4-methyl-2-oxopyridine-3-carbonitrile and its 2-hydroxy-6-oxo analog with phosphorus oxychloride gave 1-butyl-6-chloro-1,2-dihydro-4-methyl-2-oxopyridine-3-carbonitrile (68%) and 1-butyl-2-chloro-1,6-dihydro-4-methyl-6-pyridine-3-car-bonitrile (3%). Both chloropyridones were converted to their corresponding aminopyridones by reaction with liquid ammonia. Strong support for the molecular structure of 6-amino-1-butyl-1,2-dihydro-4-methyl-2-oxopyridine-3-carbonitrile was obtained on the basis of nmr techniques.     

Chemistry of siloles. The reactions of siloles with organolithium reagents

The chemical behaviour of siloles toward various organolithium reagents in THF has been investigated. The reaction of 1-methyl-1-(trimethylsilyl)-, 1-phenyl-1-(trimethylsilyl)- and 1,1-bis(trimethylsilyl)dibenzosilole (I, II and III) with a large excess of an alkyllithium such as methyllithium or butyllithium afforded 1,1-dialkyldibenzosiloles in quantitative yields. Treatment of I with an excess of phenyllithium gave a mixture of 1-methyl-1-phenyl- and 1,1-diphenyldibenzosilole quantitatively, while with an excess of tert-butyllithium, I afforded 1,1-dimethyl- and 1-tert-butyl-1-methyldibenzosilole in low yield. Similar treatment of I and II with 1 equiv. of methyl- or butyl-lithium yielded a mixture of the corresponding mono- and dialkyl-substituted dibenzosiloles. 1-Methyl-3,4-diphenyl-1,2,5-tris(trimehylsilyl)silole reacted with methyllithium in THF to give 1,1-dimethyl-3,4-diphenyl-2,2,5-tris(trimethylsilyl) silole. Similarly, both 2,4-diphenyl-1,1,3,5-tetrakis(trimethylsilyl)silole and 4,5-diphenyl-1,1,2,3-tetrakis(trimethylsilyl)silole with methyllithium afforded two isomers of 1-methyl-2,4-diphenyl-1,2,3,5-tetrakis(trimethylsilyl)-1-silacyclopent-3-ene in a ratio of 3 : 2 in high yields.     

2-甲基-1,5-苯并硫氮杂的基态和激发态反应的研究III:2-甲基-1,5-苯并硫氮杂4-(5H)-酮与-4-甲基-1,5-苯并硫氮杂-2(3H)-酮间的互变异构

用化学反应和光谱分析证实了2-甲基(1,5)苯并硫氮杂环庚三烯-4(5H)-酮和4-甲基(1,5)苯并硫氮杂环庚三烯-2(3H)-酮是作为互变异构混合物存在的.