Lower photoreactivity of 3-methyl-3-(4′-biphenylyl)-t-butene

Direct and sensitized photolyses of 3-methyl-3-(4′-biphenylyl)-1-butene gave 1,1-dimethyl-2-(4′-biphenylyl)cyclopropane as primary product and 2-methyl-4-(4′-biphenylyl)-1-butene as secondary product with quantum yields of 7.6×10^?3 and 5.6×10^?3, respectively. On direct photolysis, the triplet reactant rearranged with a quantum yield of 4.4×10^?3 and is more reactive than the singlet. The exceptionally low photoreactivity shows that the excitation energy is largely localized on the biphenylyl portion but can be delivered to the reaction center slowly.     

Photoinduzierte 1, 3-dipolare Cycloaddition von 3-Phenyl-2H-azirinen an Azodicarbonsäure-diäthylester. 32. Mitteilung über Photoreaktionen

Irradiation of 2, 2-dimethyl-3-phenyl- ( 1a ), 2, 3-diphenyl-2H-azirine ( 1b ) or the azirine-precursors 1-azido-1-phenyl-propene ( 2a ) and 1-azido-1-phenyl-ethylene ( 2b ), respectively, in benzene in the presence of azodicarboxylic acid diethylester, yields the corresponding 1, 2-carbethoxy-3-phenyl-Δ³-1, 2, 4-triazolines 4a–d (Scheme 1). Refluxing 4 ( a, c or d ) in 0, 2–0, 4M aqueous ethanolic potassium hydroxide leads to the formation of the 1-carbethoxy-3-phenyl-Δ²-1, 2, 4-triazolines 6 ( a, c or d ). Under the same conditions 4b is converted to 3, 5-diphenyl-1, 2, 4-triazole ( 7b , Scheme 2). In 10M aqueous potassium hydroxide solution heating of either 4 ( c or d ) or 6 ( c or d ) yields the 3-phenyl-1, 2, 4-triazoles 7 ( c or d ). Photolysis of 1-carbethoxy-5, 5-dimethyl-3-phenyl-Δ²-1, 2, 4-triazoline ( 6a ) in benzene in the presence of oxygen and trifluoroacetic acid methylester gives the 5-methoxy-2, 2-dimethyl-4-phenyl-5-trifluoromethyl-3-oxazoline ( 13 , Scheme 5). 5, 5-Dimethyl-3-phenyl-1, 2, 4-triazole seems to be the intermediate, which on losing nitrogen gives the benzonitrile-isopropylide ( 3a ).     

4,5-Dioxo-and 4-oxo-2,3-diaryl-5-diazo-6,6-dimethyl-4,5,6,7-tetrahydroindazoles

The oxidation of 2,3-diphenyl-, 3-(4-chlorophenyl)-2-phenyl-, 3-(4-dimethylaminophenyl)-2-phenyl-, 3-(4-methoxyphenyl)-2-phenyl-, 2-phenyl-3-(3-pyridyl)-, 3-phenyl-2-(2-pyridyl)-, and 3-(4-dimethylaminophenyl)-6,6-dimethyl-4-oxo-2-(2-pyridyl)-4,5,6,7-tetrahydroindazoles using H₂SeO₃ in acetic acid in the presence of sulfuric acid gave the corresponding 4,5-dioxo derivatives. Reaction of these with tosylhydrazine gave 4-oxo-5-tosylhydrazino derivatives which were decomposed by alkali to give the corresponding 2,3-diaryl-5-diazo-6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazoles. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1829–1833, December, 2005     

Synthèse de N-Alkyl-arylamines par Thermolyse ou Photolyse d'Alkyl-3-diaryl-1,3-triazènes

Synthesis of N-Alkyl-arylamines by Thermolysis or Photolysis of 3-Alkyl-1,3-bis(p-chlorophenyl)triazenes The thermolysis of 3-alkyl-1,3-bis(p-chlorophenyl)triazenes in benzene or methanol leads to the formation of N-alkyl-p-chloroanilines ( 2 ) in 19–50% yield, N-alkyl-bis(p-chlorophenyl)amines ( 3 ) in 7.5–15.5% yield and 4,4′-dichlorobiphenyle ( 4 ) in 1–7% yield; besides with benzene as the substrate, 4-chlorobiphenyle ( 5 ) (12–20% yield) was also formed. The photolysis in methanol gives only the N-alkyl-p-chloroanilines ( 2 ) in 32–40% yield. In these two cases the results are consistent with a radical pair formation in a solvent cage, recombination (thermolysis) and/or diffusion (thermolysis and photolysis) with intermolecular abstraction of hydrogen. A free radical chain mechanism is involved in the photolytic process and the quantum yield is high.     

The mechanism of thermal elimination of urea and thiourea derivatives. Part 2. Rate data for pyrolysis of N-acetyl-N′-phenylthiourea and N-benzoyl-N′-arylthioureas

The first-order rate constants of N-acetyl-N′-phenylthiourea (1), N-benzoyl-N′-phenyl-(2a), N-benzoyl-N′-(4-nitrophenyl)-(2b), N-benzoyl-N′-(3-chlorophenyl) (2c), N-benzoyl-N′-(4-chlorophenyl) (2d), and N-benzoyl-N′-(4-methylphenyl)thiourea (2e) were measured between 423 and 500 K. The reactions were homogeneous and unimolecular with log A (s⁻¹) = 12.0, 13.2, 13.8, 10.9, 11.8, and 12.7 and E_a kJ mol⁻¹ = 130.3, 141.4, 134.6, 114.9, 124.1, and 141.1, respectively. The rate data gave good Hammett correlation with σ^o values, and ρ is 1.99 at 450 K. © 1997 John Wiley & Sons, Inc.     

Zur addition von nucleophilen an C(2) heterocyclischer 2-methylsubstituierter quartärsalze

1-(4-Chlorophenyl)-2-methyl-3-phenylquinoxalinium perchlorate ( 5 ) obtained by two different routes, on treating with nucleophiles HX or X⁻ yielded 1,3-diaryl-2-methyl-2X-1,2-dihydroquinoxalines 10 . Alkylation of 10e yielded 4-(4-chlorophenyl)-1,3-dimethyl-3-nitromethyl-2-phenyl-3,4-dihydroquinoxalinium perchlorate ( 11e ). The ¹H-nmr and mass spectra are presented. Diastereoisomerism of the products is discussed.     

Photochemische Synthesen potentiell hypoglykämisch wirkender 3-Oxazoline

Photochemical Syntheses of 3-Oxazolines which Possibly Exhibit Hypoglycemic Activity Reactions of photochemically generated benzonitrile methylides 2 with carbonyl compounds 3 yielded 3-oxazolines of the types 5 and 6 (Scheme 1). Photooxidation of 5-[p-(dimethylamino)phenyl]-2,2-dimethyl-4-phenyl-3-oxazoline ( 5a ) gave 4′-(2,2-dimethyl-4-phenyl-3-oxazolin-5-yl)-N-methylformanilide ( 6r ) which could be transformed to 2,2-dimethyl-5-[p-(methylamino)phenyl]-4-phenyl-3-oxazoline ( 6s ) by photodecarbonylation. Thirty 3-oxazolines of types 5 and 6 have been synthesized and tested by oral and/or intraperitoneal administration to starved rats and obese-hyperglycemic mice.     

Synthesis and debenzoylation products of two perbenzoylated 2-substituted 5-D-galactosyl-1,3,4-oxadiazoles

The synthesis of 2-(p-chlorophenyl)-5-[1′,2′,3′,4′,5′-penta-O-benzoyl-D-galactopentitol-1-yl]-1,3,4-oxadiazole is described. Its debenzoylation gave an equilibrium mixture of the 1,3,4-oxadiazole derivative without protection of the hydroxyl group and the N-benzoyl-D-galactono-1,4-lactonehydrazone. A similar equilibrium was observed by debenzoylation of 2-phenyl-5-[1′,2′,3′,4′,5′-penta-O-benzoyl-D-galactopentitol-1-yl]-1,3,4-oxadiazole. The ¹H, ¹³C nmr and ms spectra of these compounds are presented.     

二芳杂环基乙烯的合成及其光致变色反应研究

本文报道了2,3-双 (1,2-二甲基-3-吲哚基)-2-丁烯 (DF1),2,3-双 (1,4-二苯基-2-甲基-3-吡咯基)-2-丁烯 (DF2), 2,3-双(1-对甲苯基-4-苯基-2-甲基-3-吡咯基)-2-丁烯 (DF3), 2,3-双(1-对溴苯基-4-苯基-2-甲基-3-吡咯基)-2-丁烯 (DF4) 和2,3-双 (1-对甲氧苯基-5-苯基-2-甲基-3-吡咯基)-2-丁烯 (DF5) 的合成,以及它们的光致变色行为的研究。特别是DF1和DF5的光呈色和光消色过程进行了较为细致的研究。     

Studies on the synthesis of heterocyclic compounds. Part IV. Further investigation of the pschorr reaction with some pyrazole derivatives

Thermal decomposition of the diazonium sulfate derived from N-methyl-(1-phenyl-3-methylpyrazol-5-yl)-2-aminobenzamide afforded products formulated as 1-phenyl-3-methyl[2]benzopyrano[4,3-c]pyrazol-5-one (yield 10%), 1,4-dimethyl-3-phenylpyrazolo[3,4-c]isoquinolin-5-one (yield 10%), N-methyl-(1-phenyl-3-methylpyrazol-5-yl)-2-hydroxybenzamide (yield 8%) and 4′-hydroxy-2,3′-dimethyl-1′-phenylspiro[isoindoline-1,5′-[2]-pyrazolin]-3-one (yield 20%). Decomposition of the diazonium sulfate derived from N-methyl-(1,3-diphenylpyrazol-5-yl)-2-aminobenzamide gave products formulated as 7,9-dimethyldibenzo[e,g]pyrazolo[1,5-a][1,3]-diazocin-10-(9H)one (yield 8%), 4-methyl-1,3-diphenylpyrazolo[3,4-c]isoquinolin-5-one (yield 7%) and 4′-hydroxy-2-methyl-1′,3′-diphenylspiro[isoindoline-1,5′-[2]pyrazolin]3-one (yield 10%). The spiro compounds 6a,b underwent thermal and acid-catalysed conversion into the hitherto unknown 2-benzopyrano[4,3-c]pyrazole ring system 7a,b in good yield. Analytical and spectral data are presented which supported the structures proposed.     

Studies on the syntheses of azole derivatives. Part VII. Syntheses of 1 -phenyl-Δ2-1,2,4-triazolin-5-one derivatives [studies on the syntheses of heteroeyclic compounds. CD XI]

Bromination of 3-methyl-1-phenyl-Δ²-1,2,3-lriazolin-5-one (II) and its 4-phenyl derivative III afforded the corresponding I-(p-Bromophenyl) derivatives IV and V, respectively. (Chlorination of the 4-phenyl derivative III gave I-(P-chlorophenyl) derivative VI. In addition, 3-N-subsuituted-carhamoyl-1,2,4-triazolin-5-ones(XII, XIII, and XIV) were synthesized by the Schotten-Baumann reaction of 3-carboxy-1-phenyl-Δ²-1,2,4-triazolin-5-one (XI) with various amines.     

Rate coefficients for the gas-phase reactions of bromine radicals with a series of alkenes,dienes, and aromatic hydrocarbons at 298 ± 2 K

Using the relative kinetic method rate coefficients have been determined for the gas-phase reaction of bromine (Br) radicals with a series of alkenes, chloroalkenes, dienes, and aromatic hydrocarbons in 1000 mbar of synthetic air at 298 ± 2 K. Both the UV photolysis of CH₂Br₂ (λ = 254 nm) and the visible photolysis of Br₂ (320 ≤ λ ≤ 480) were used to generate Br radicals. For the alkenes and dienes the following rate coefficients were obtained (in units of 10⁻¹² cm³ molecule⁻¹ s⁻¹): trans-2-butene 9.26 ± 1.85; 2-methyl-1-butene 15.20 ± 3.00; 2-methyl-2-butene 19.10 ± 3.80; 2,3-dimethyl-2-butene 28.20 ± 5.60; α-pinene 22.20 ± 4.40. β-pinene 28.60 ± 5.70; 1,3-butadiene 57.50 ± 11.50; isoprene 74.20 ± 14.80; and 2,3-dimethyl-1,3-butadiene 81.7 ± 16.30. For the chloroalkenes and aromatic hydrocarbons the following rate coefficients were obtained (in units of 10⁻¹³ cm³ molecule⁻¹ s⁻¹): chloroethene 7.37 ± 1.92; 1,1-dichloroethene 3.66 ± 0.73; trichloroethene 0.90 ± 0.18; tetrachloroethene ≤ 0.1; benzene ≤ 0.10; toluene ≤ 0.10; p-xylene ≤ 0.10; and furan ≤ 0.10. With the exception of trans-2-butene, this study represents the first determination of the rate coefficients for all of the compounds. © 1996 John Wiley & Sons, Inc.     

Photo- and thermal elimination of nitrogen from 4-phenyl- and 4,5-diphenyl-1,2,3-triazole

Phenylacetonitrile ( 2 ) (32%) and small amounts of benzyl methyl ether ( 3 ), benzonitrile ( 5 ) and methyl benzoate ( 6 ) were produced by irradiation of either 4-phenyl-1,2,3-triazole ( 1 ) or 4-phenyl-5-deutero-1,2,3-triazole ( 7 ) in methanol at 254 nm. In methylene chloride, irradiation of 1 produced 2 (15%) and small amounts of 3,6-diphenyl-1,2,4,5-tetrazine ( 8 ). Irradiation of 4,5-diphenyl-1,2,3-triazole ( 9 ) in methanol gave 2,4,5-triphenylimidazole ( 11 ) (4%) and trace amounts of diphenylacetonitrile ( 10 ), benzamide ( 12 ), and compounds 3 , 5 , and 6 . Irradiation of 2,3-diphenyl-2H-azirine ( 13 ) in methanol gave small amounts of 3 , benzaldehyde ( 4 ), and compounds 5 , 6 , 12 as well as 2,3,5,6-tetraphenylpyrazine ( 14 ) and in methylene chloride it gave 11 (16%) and small amounts of 4 , 5 , 14 , and acetophenone ( 15 ). On heating 4-phenyl-1,2,3-triazole ( 1 ) in n-hexadecane, elimination of nitrogen at 290° left phenylacetonitrile ( 2 ) as the only identified product. Similar pyrolysis of 4,5-diphenyl-1,2,3-triazole ( 9 ) produced 2,3,5,6-tetraphenylpyrazine ( 14 ) along with an intractable material. An efficient thermal isomerization of 2,3-diphenyl-2H-azirine ( 13 ) gave 2-phenylindole ( 17 ).     

Synthesis,characterization, and antioxidant activity of heterocyclic Schiff bases

Schiff base derivatives have gained great importance due to revealing a great number of biological properties. Schiff bases were synthesized by treatment of 4-amino-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one ( 1 ) with various aldehydes in methanol at reflux. In addition, diamine was reacted with an aldehyde to yield the corresponding Schiff bases. The structures of synthesized Schiff bases were elucidated by spectroscopic methods such as microanalysis, ¹H-NMR, ¹³C-NMR, and FTIR. Antioxidant activities of synthesized Schiff bases were carried out using different antioxidant assays such as 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH^•) scavenging, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging, and reducing power activity. (E)-4-((1H-indol-3-yl)methyleneamino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one ( 3 ), (E)-1,5-dimethyl-4-((2-methyl-1H-indol-3-yl)methyleneamino)-2-phenyl-1H-pyrazol-3(2H)-one ( 5 ), (E)-1,5-dimethyl-2-phenyl-4-(thiophen-2-ylmethyleneamino)-1H-pyrazol-3(2H)-one ( 7 ), (E)-1,5-dimethyl-2-phenyl-4-(quinolin-2-ylmethyleneamino)-1H-pyrazol-3(2H)-one ( 9 ), (1S,2S,N1,N2)-N1,N2-bis((1H-indol-3-yl)methylene)cyclohexane-1,2-diamine ( 11 ), and (1S,2S,N1,N2)-N1,N2-bis((2-methyl-1H-indol-3-yl)methylene)cyclohexane-1,2-diamine ( 12 ) were synthesized in high yields. Compound 5 displayed a good ABTS^•+ activity. Compound 3 revealed the outstanding activity in all assays. Compound 7 has the best-reducing power ability in comparison to other synthesized compounds. Although compounds 5, 11, 12 are new, compounds 3, 7, 9 are known. Due to revealing a good antioxidant activity, the synthesized compounds ( 3, 5, 7 ) have the potential to be used as synthetic antioxidant agents.     

Silicon-carbon unsaturated compounds: XXX. thermal isomerization of 1-mesityl-3-phenyl-1,2-bis(trimethylsilyl)-1-silacyclopropene and 2-mesityl-2-(phenylethynyl)hexamethyltrisilane

The thermolysis of 1-mesityl-3-phenyl-1,2-bis(trimethylsilyl)-1-silacyclopropene at 280°C afforded 1-mesityl-3,3-dimethyl-4-phenyl-5-(trimethylsilyl)-1,3-disilacyclo-4-pentene and 1-mesityl-1,3-bis(trimethylsily)-1-silaindene. Similar thermolysis of 2-mesityl-2-(phenylethynel)hexamethyltrisilane produced the same products.     

Thermal decomposition of 2-amino-3-aziridino-1,4-naphthoquinones

The course of the thermal decomposition of various 2-amino-3-substituted aziridino-1,4-naphthoquinones (Ia-g) was investigated. In all the cases, the thermal decomposition gave variable amounts of 2,3-diamino-1,4-naphthoquinone (II) and of substituted 1,2,3,4,5,10-hexahydrobenzo[g]quinoxaline-5,10-diones (IIIa-g) with complete stereospecificity. The decomposition of the aziridines Ib,f also gave significative amounts of 2-amino-3-allylamino-1,4-naphthoquinones (IVb,f). In the case of 2-amino-3-(2′-phenyl-3′-ethylaziridino)-1,4-naphthoquinone (Ig), the formation of trans-1-phenyl-1-butene (V), 2-(1-phenylpropyl)-1H-naphtho-imidazole-4,9-dione (VI), 2-phenyl-3-ethyl-3,4,5,10-tetrahydrobenzo[g]quinoxaline-5,10-dione (VII), 2-phenyl-3-ethyl-5,10-dihydrobenzo[g]quinoxaline-5,10-dione (VIII), and a mixture of cis- and trans-4H-2,3,5,6-tetra-hydro-2-phenyl-3-ethyl-5-iminonaphtho[1,2-b]oxazin-6-one (IX) also occurred. Hypotheses concerning the mechanism and the steric course of this reaction are given. The reaction is a general method for the stereospecific synthesis of 2,3-disubstituted 1,2,3,4,5,10-hexahydrobenzo[g]quinoxalines.     

4(3H)-Quinazolinones containing heterocyclic group in position 3

The corresponding 2,3-substituted 4(3H)-quinazolinones were obtained in the reactions of 2-methyl- and 2-phenyl-4-oxo-3,1-benzoxazines with 1-amino-1,2,4-triazole, 4-amino-2,3-dimethyl-1-phenyl-5-pyrazolone, 2-amino-5-ethyl-1,3,4-thiadiazole, 3-amino-6,6-dimethyl-4-oxo-4,5,6,7-tetrahydroindazole, 1-amino-3-cyano-4,6-dimethyl-2-pyridone, and 1-amino-3-cyano-6-phenyl-4-trifluoromethyl-2-pyridone. The formation of N-benzolyanthranilamides in the reactions of 2-phenyl-4-oxo-3,1-benzoxazine with 2-amino-5-ethyl-1,3,4-thiadiazole and 1-amino-3-cyano-6-phenyl-4-trifluoromethyl-2-pyridones was exceptional. The structures of two of the products have been confirmed by X-ray crystallography.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 936–943, July, 2000.     

Stereoselective Methods for the Synthesis of 4-Benzoyl-1-benzoylamino-3-(2-chlorophenyl)-2-cyano-1-methylthio-1-butene and Its Structure

Selective methods were developed for the synthesis of 4-benzoyl-1-benzoylamino-3-(2-chlorophenyl)-2-cyano-1-methylthio-1-butene on the basis of the reaction of N-methylmorpholinium and piperidinium 5-benzoyl-4-(2-chlorophenyl)-3-cyano-6-hydroxy-6-phenyl-1,4,5,6-tetrahydropyridine-2-thiolates with methyl iodide. The structure of the product was established by X-ray crystallographic analysis.     

Silicon-carbon unsaturated compounds. 73. Photolysis of cis- and trans-1,2-dimethyl-1,2-diphenyl-1,2-disilacyclohexane in the presence of tert-butyl alcohol and acetone

Irradiation of cis-1,2-dimethyl-1,2-diphenyl-1,2-disilacyclohexane (1a) in the presence of tert-butyl alcohol in hexane with a low-pressure mercury lamp bearing a Vycor filter proceeded with high stereospecificity to give cis-2,3-benzo-1-tert-butoxy-1,4-dimethyl-4-phenyl-1,4-disilacyclooct-2-ene (2a), in 33% isolated yield, together with a 15% yield of 1-[(tert-butoxy)methylphenylsilyl]-4-(methylphenylsilyl)butane (3). The photolysis of trans-1,2-dimethyl-1,2-diphenyl-1,2-disilacyclohexane (1b) with tert-butyl alcohol under the same conditions gave stereospecifically trans-2,3-benzo-1-tert-butoxy-1,4-dimethyl-4-phenyl-1,4-disilacyclooct-2-ene (2b) in 41% isolated yield, along with a 12% yield of 3. Similar photolysis of 1a and 1b with tert-butyl alcohol-d₁ produced 2a and 2b, respectively, in addition to 1-[(tert-butoxy)(monodeuteriomethyl)(phenyl)silyl]-4-(methylphenylsilyl)butane. When 1a and 1b were photolyzed with acetone in a hexane solution, cis- and trans-2,3-benzo-1-isopropoxy-1,4-dimethyl-4-phenyl-1,4-disilacyclooct-2-ene (4a and 4b) were obtained in 25% and 23% isolated yield. In both photolyses, 1-(hydroxymethylphenylsilyl)-4-(methylphenylsilyl)butane (5) was also isolated in 4% and 5% yield, respectively. The photolysis of 1a with acetone-d₆ under the same conditions gave 4a-d₆ and 5-d₁ in 18% and 4% yields.     

Rate constants for the reactions of OH radicals with alkyl substituted olefins

Relative rate constants for the reactions of hydroxyl radicals with a series of alkyl substituted olefins were measured by competitive reactions between pairs of olefins at 298 ± 2 K and 1 atmospheric pressure. Hydroxyl radicals were produced by the photolysis of H₂O₂ with 254-nm irradiation. The obtained rate constants were (× 10^?11 cm³ molecule^?1 s^?1): 2.53 ± 0.06, propylene; 5.49 ± 0.17, cis-2-butene; 5.47 ± 0.1, isobutene; 6.46 ± 0.13, 2-methyl-1-butene; 6.37 ± 0.16, cis-2-pentene; 6.23 ± 0.1, 2-methyl-1-pentene; 8.76 ± 0.14, 2-methyl-2-pentene; 6.24 ± 0.08, trans-4-methyl-2-pentene; 10.3 ± 0.1, 2,3-dimethyl-2-butene; 9.94 ± 0.1, 2,3-dimethyl-2-pentene; 5.59 ± 0.07, trans-4,4-dimethyl-2-pentene. A trend in alkyl substituent effect on the rate constant was found, which is useful to predict k_OH on the basis of the number of alkyl substituents on the double bond.