The fluorination of benzene over manganese trifluoride

Flourination of benzene, in the vapour phase, over manganic fluoride at 300° has given undecafluorocylohexane (3.5%); 1H-, 3H- and 4H-nonafluorocyclohexene (3.3, 0.2 and 1.6%, respectively); 1H/2H- and 1H/4H-decafluorocyclohexane (1.1 and 6.2%, respectively); 1H,4H-hexafluorocyclohexa-1:4-diene (4.0%); 1H,2H- and 1H,4H-octafluorocyclohexene (0.04 and 15.8%, respectively); floruo- (3.9%), p-difluoro- and 1,2,4-trifluoro-benzene; 1H4H/2H, 1H/2H,4H- and 1H,2H/4H-nonafluorocyclohexane; and 1H,3H/4H-, 1H,4H/5H- and 1H, 2H,4H- (8.0%) heptafluorocyclohexene.     

Synthesis of (+)-pechueloic acid and (+)-aciphyllene. Revision of the structure of (+)-aciphyllene

1αH,7αH,10αH-Guaia-4,11-dien-3-one and its 1βH,10βH diastereomer, easily obtained from (+)-dihydrocarvone, are good starting materials for the synthesis of natural guaiane derivatives. Allylic oxidation of the 1αH,10αH isomer gave as main product its 13-hydroxy derivative and a small amount of (+)-7β-hydroxy-1αH,10αH-guaia-4,11-dien-3-one, whereas the 1βH,10βH diastereomer afforded selectively the (−)-7α-hydroxy-1βH,10βH enantiomer in excellent yield. From the 13-hydroxy derivative (+)-pechueloic acid and (+)-methyl pechueloate were synthesized. Deoxygenation at C₃ of the 1βH,10βH guaiadienone afforded a guaiadiene with the reported structure for aciphyllene but its spectral data did not agree with those reported for the natural diene. The structure of natural (+)-aciphyllene has been corrected to 1αH,7αH,10αH-guaia-4,11-diene obtained by deoxygenation of the 1αH,10αH guaiadienone.     

Esterification of polyfluoroalkyl alcohols with tall oil rosin

Acid-catalyzed nonsolvent esterification of 1H,1H,5H-perfluoropentan-1-ol, 1H,1H,7H-perfluoroheptan-1-ol, and 1H,1H,9H-perfluorononan-1-ol with tall oil rosin was studied.     

Reaction of 3-phenyl-3-aminoquinoline-2,4-diones with isothiocyanates. Facile access to novel spiro-linked 2-thioxoimidazolidine-oxindoles and imidazoline-2-thiones

3-Phenyl-3-amino-1H,3H-quinoline-2,4-diones (1) react with alkyl or aryl isothiocyanates to give novel 9b-hydroxy-3a-phenyl-1,2,3,3a-tetrahydro-2-thioxo-5H-imidazo[4,5-c]quinolin-4(9bH)-ones in high yields. These compounds rearrange in boiling acetic acid or concentrated hydrochloric acid to give novel 5-phenyl-2-thioxospiro[4H-imidazol-4,3′-[3H]indol]-2′(1′H,3H)-ones, 5-hydroxy-5-phenyl-2-thioxospiro[imidazolidine-4,3′-[3H]indol]-2′-ones and (2-methylaminophenyl)-5-phenyl-1H-imidazole-2(3H)-thiones. All compounds were characterized by their ¹H, ¹³C, IR and MS data, and in some cases also by ¹⁵N NMR data. The structures and compositions of four compounds were confirmed by single crystal X-ray diffraction.     

Flash vacuum pyrolysis of 2,2-dioxo-1H,3H-pyrrolo[1,2-c]thiazoles and 2-vinyl-1H-pyrroles

The flash vacuum pyrolysis of new 1,1-dimethyl- and 1-methyl-1H,3H-pyrrolo[1,2-c]thiazole-2,2-dioxides gave penta-substituted 2-vinyl-1H-pyrroles via sigmatropic [1,8]-H shift of the corresponding azafulvenium methide intermediates. In some cases these 1H-pyrroles underwent rearrangement to 2-allyl-1H-pyrroles. Di-substituted 2-vinylpyrroles have also been prepared and their reactivity studied. Under FVP N-benzyl-pyrrol-2-ylpropenoates were converted into 3H-pyrrolizin-3-ones. On the other hand, microwave-assisted reaction of 1-benzyl-2-vinyl-1H-pyrrole gave a 4,5,6,7-tetrahydro-1H-indole derivative.     

Application of N,3-diaryl-3-oxo-propanethioamide in synthesis: an efficient and mild domino approach to highly substituted fused chromenones

A convenient and rapid synthesis of hitherto unknown 3-aroyl-4-aryl-2-phenylamino-4H-benzo[g]chromene-5,10-diones in high yield from β-aroyl-thioacetanilide, aromatic aldehyde, and 2-hydroxy-1,4-naphthoquinone via InCl₃ catalyzed one-pot three-component tandem Knoevenagel condensation–Michael addition–intramolecular cyclization–elimination reaction sequence is disclosed for the first time. This domino protocol has been used to obtain highly substituted pyrano[3,2-c]chromen-5(4H)-ones and 7,7-dimethyl-7,8-dihydro-4H-chromen-5(6H)-ones from N,3-diaryl-3-oxo-propanethioamide, aromatic aldehyde, and 4-hydroxycoumarine or dimedone under mild reaction conditions. A plausible reaction mechanism is proposed. The 4H-pyrano[3,2-c]chromen-5-one and 7,7-dimethyl-7,8-dihydro-4H-chromen-5(6H)-one derivatives possessing 3-(2-chlorobenzoyl)-2-phenylamino-substituents further cyclized under basic conditions to yield penta-cyclic 7,13-diaryl-5,14-dioxa-13-aza-benzo[a]naphthacen-6,8(7H,13H)-dione and tetra-cyclic 6,12-diaryl-3,3-dimethyl-3,4-dihydro-2H-chromeno[2,3-b]quinolin-1,11(6H,12H)-dione, respectively.     

Preparation of fluorinated esters of abietic acid

The reaction of abietic acid chloride with sodium salts of 1H,1H-dihydrotrifluoroethanol, 1H,1H,3H-trihydrotetrafluoropropanol, 1H,1H,5H-trihydrooctafluoropentanol, and pentafluorophenol was studied. The main reaction products are the corresponding fluorinated alkyl (aryl) abietates.     

Synthesis of new thietanylpyrimidine and thietanylimidazole derivatives

New thietanyl-substituted derivatives of pyrimidine-2,4(1H,3H)-dione and imidazole were synthesized. The alkylation of 6-methylpyrimidine-2,4(1H,3H)-diones with 2-chloromethylthiirane in water involved the N¹ atom of the pyrimidine ring and afforded 6-methyl-1-(thietan-3-yl)-pyrimidine-2,4(1H,3H)-diones. Under analogous conditions 6-aminopyrimidine-2,4(1H,3H)-dione gave rise to 6-(thietan-3-ylamino)pyrimidine-2,4(1H,3H)-dione. Unsymmetrically substituted 2-methyl-4(5)-nitro- and 5(4)-bromo-2-methyl-4(5)-nitro-1H-imidazoles reacted with 2-chloromethylthiirane to produce mixtures of isomeric 2-methyl-4(5)-nitro-1-(thietan-3-yl)-1H-imidazoles and 5(4)-bromo-2-methyl-4(5)-nitro-1-(thietan-3-yl)-1H-imidazoles.     

Oxidative alkylamination of azinones as a direct route to aminoazinones: study of some condensed diazinones

Oxidative alkylamination of azinones is a promising method for the preparation of a great variety of alkylaminoazinones. Treatment of 6,8-dimethyl-2-R-pyrimido[4,5-c]pyridazin-3,5,7(2H,6H,8H)-triones 7, 1,3-dimethyl-5-R-pteridin-2,4,6(1H,3H,6H)-triones 8 and 1,3,6-trimethylpyrimido[4,5-d]pyrimidin-2,4,7(1H,3H,6H)-trione 9 with alkylamine/AgPy₂MnO₄ or alkylamine/KMnO₄ has been shown to produce their 4-, 7- and 5-alkylamino derivatives, respectively, in good yields. While 1-methylquinoxalin-2(1H)-one 10 is smoothly alkylaminated under the above conditions giving 3-alkylamino derivatives, quinoxaline itself does not take part in this reaction. Factors influencing oxidative alkylamination of azinones and a regioselectivity of the process are discussed.     

Electrophoretic determination of phenyl and p-bromophenyl substituted 1H,2H,3H,4H-pyrido[4,3-d]pyrimidinium diiodobromides

Phenyl and p-bromophenyl substituted 1H,2H,3H,4H-pyrido[4,3-d]pyrimidinium diiodobromides have been identified and determined by capillary zone electrophoresis on an unmodified quartz capillary. It has been found that an increase in the number of bromine atoms in the structure of 1H,2H,3H,4H-pyrido[4,3-d]pyrimidinium derivatives consecutively decreases the electrophoretic mobility of the cations. The developed method makes possible the determination pyrido[4,3-d]pyrimidinium derivatives in the concentration range (0.03–0.25) mM with the c _min (3.1–10.0) μM.     

Fluorination of alcohols and diols with a novel fluorous deoxy-fluorination reagent

We prepared a novel fluorous deoxy-fluorination reagent N,N-diethyl-α,α-difluoro-[3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzyl]amine (1b) from 3,5-diiodobenzoic acid (3b) via N,N-diethyl-3,5-bis(1H,1H,2H,2H-perfluorodecyl)benzamide (2b) in four steps and used it for the fluorination of alcohols and diols. After the fluorination reactions, the isolation of the products and recovery of 2b was performed by extraction with a fluorous/organic solvent system.     

Alignment behavior for novel triphenylene compounds possessing fluoroalkylated side chains on modified substrates

The alignment behavior of the triphenylene compounds possessing fluoroalkylated side chains was investigated for the hexagonal columnar (Col_h) mesophase on the polyimide-, cetyltrimethylammonium bromide (CTAB)-, and indium-SnO₂ (ITO)-coated glass substrates by polarizing optical microscopy. It was found that 2,3,6,7,10,11-hexakis(1H,1H,2H,2H,3H,3H-perfluoroheptyloxy)- and 2,3,6,7,10,11-hexakis(1H,1H,2H,2H,3H,3H-perfluorononyloxy)-triphenylenes exhibit a spontaneous homeotropic alignment on these substrates, in contrast to the non-uniformity of alignment of Col_h phase in the corresponding hydrocarbon mesogens. On the other hand, it was also found that 4,4,4-trifluorobutyloxy, 4,4,5,5,5-pentafluoropentyloxy and 4,4,5,5,6,6,6-heptafluorohexyloxy derivatives do not show such a spontaneous homeotropic alignment on these substrates. These results indicate that the spontaneous homeotropic alignment of the Col_h phase could be easily attained by the introduction of an appropriate number and length of the fluoromethylene chains in the peripheral parts of discogens.     

The synthesis of functional derivatives of the [1-CB9H10] anion by Brellochs reaction

Reactions of decaborane with various aldehydes in alkaline media were studied. The reactions with HCOH and 2-MeOC₆H₄CHO give the corresponding arachno-carboranes [6-R-arachno-CB₉H₁₃]⁻ (R = H, C₆H₄-2-OMe), whereas the reactions with C₆H₅CHO, 4-BrC₆H₄CHO, 4-MeCONHC₆H₄CHO, and 2-SC₄H₃CHO result in the nido-carboranes [6-R-nido-CB₉H₁₁]⁻ (R = C₆H₅, C₆H₄-4-Br, C₆H₄-4-NHCOMe, 2-SC₄H₃). Both the arachno- and nido-carboranes can be easily oxidized with elemental iodine in an alkaline aqueous solution giving the corresponding closo-derivatives [2-R-closo-2-CB₉H₉]⁻. These closo-2-isomers, under heating in solution, undergo rearrangement to more thermodynamically favorable closo-1-isomers [1-R-closo-1-CB₉H₉]⁻. The structure of (Bu₄N)[1-(4-BrC₆H₄)-1-CB₉H₉] was determined using single crystal X-ray diffraction.     

Design and synthesis of novel 5,6-bisindolylpyrimidin-4-ones structurally related to ruboxistaurin (LY333531)

2,3-Bis(1-methyl-1H-indol-3-yl) methyl-3-oxopropionate is a key intermediate in the synthesis of a new family of LY333531 analogues. Base-mediated cyclocondensation with thiourea afforded novel 5,6-bis(1-methyl-1H-indol-3-yl)-2-thioxo-2,3-dihydropyrimidin-4(1H)-one, which was efficiently converted to the pyrimidin-2,4(1H,3H)-dione congener. Synthesis of a six-membered K-252c analogue, 5,6-bis(1-methyl-1H-indol-3-yl)pyrimidin-4(3H)-one, is also described.     

Non-catalyzed addition of heterocyclic thiols and 5-substituted-1H-tetrazoles to vinyl ethers

The alkylation of 1-substituted 1H-tetrazole-5-thiols and 4-substituted 4 H-1,2,4-triazole-3-thiols with alkyl halides or sulfonates lead to the formation of S-alkylated products regardless of the substituent on the heterocycle. In this work, we found that substituted 1H-tetrazole-5-thiols and 4 H-1,2,4-triazole-3-thiols readily reacted with vinyl ethers in the absence of a catalyst to exclusively form N-substituted 1H-tetrazole-5(4H)-thiones and 1H-1,2,4-triazole-5(4H)-thiones, respectively. Furthermore, the reactions of 5-substituted-1H-tetrazoles with vinyl ethers under the same conditions selectively yielded 2,5-disubstitued tetrazoles.     

Reaktion der Tautomeren 4-Hydroxy-2H-thiopyran-2-thion und 2-Mercapto-4H-thiopyran-4-on mit aliphatischen Aldehyden

5,6-Dihydro-4-hydroxy-6,6-dimethyl-2H-thiopyrane-2-thione (1 I) and its tautomer 2-mercapto-4H-thiopyrane-4-one (1 II) react with aliphatic aldehydes under different reaction conditions to yield mainly 5R-7,8-dihydro-2H,5H,6H-thiopyrano[2,3—b:6,5—b′]-bisthiopyran-4,6(3H)-diones2 and 2′R,4′R-5,6,6′,7′-tetrahydro-2-thioxo-spiro(4H-thiopyran-3(2H), 3′(4′H)-2′H,5′H-thiopyrano-[2,3—b]-thiopyran)-4,5′-diones3. The mechanisms of formation of the condensates2 and3 and their stereochemistry are discussed. The reaction yielding2 is analogous to the condensation of dimedone with subsequent anhydride formation.3 might be generated byDiels-Adler reaction of intermediately formed 2-thioxo-3-alkylidenethiopyranones4. An X-ray crystal structure analysis was carried out on3 b to establish its configuration and conformation.     

Synthesis of 3-methylquinazolin-4(3H)-one derivatives

Oxidation of 3-methyl-2-sulfanylquinazolin-4(3H)-one with chlorine dioxide under different conditions gave 2,2??-disulfanediylbis[3-methylquinazolin-4(3H)-one], 3-methyl-4-oxo-3,4-dihydroquinazoline-2-sulfonic acid, 3-methylquinazoline-2,4(1H,3H)-dione, 6-chloro-3-methylquinazoline-2,4(1H,3H)-dione, and N,N-diethyl-3-methyl-4-oxo-3,4-dihydroquinazoline-2-sulfonamide.     

Synthesis of perfluoroalkyl-containing multifunctional groups compounds for textile finishing

A new kind of perfluoroalkyl-containing multifunctional groups compound was designed. Treatment of 1H,1H,2H,2H-perfluorooctyltrichlorosilane (4) with allylmagnesium bromide provided key intermediate 1H,1H,2H,2H-perfluorooctyltriallylsilane (2). Hydroboration followed by oxidation, epoxidation and dihydroxylation of 2 gave perfluoroalkyl-containing multifunctional groups compound 1a, 1b and 1c, respectively.     

Synthesis of (1H-pyrrol-2-ylsulfanyl)alkanoic acids

(1-Benzyl-1H-pyrrol-2-ylsulfanyl)acetic acid, 2- and 3-(1-benzyl-1H-pyrrol-2-ylsulfanyl)propionic acids, 1,1′-[1,4-phenylenebis(methylene)]bis[(1H-pyrrol-2-ylsulfanyl)acetic acid], and 1,1′-(hexane-1,6-diyl)bis-[(1H-pyrrol-2-ylsulfanyl)acetic acid] were synthesized for the first time by reactions of 1-benzyl-1H-pyrrole, 1,1′-[1,4-phenylenebis(methylene)]bis(1H-pyrrole), and 1,1′-(hexane-1,6-diyl)bis(1H-pyrrole) with thiourea, iodine, and the corresponding halogen-substituted alkanoic acids. 1-(4-Nitrophenyl)-1H-pyrrole failed to react with thiourea and iodine.     

Rotational and vibrational distributions of N2(C 3Πu) excited by state-selected Ar(3P2) and Ar(3P0) metastable atoms

The ESR method is used to study the oxidation kinetics of the CH₃, C₂H₅, n-C₄H₉, i-C₄H₉, s-C₄H₉, t-C₄H₉, n-C₆H₁₃, C₆H₁₁, C₆H₅CH₂, CH₃C₆H₄CH₂, and C₆H₅CH₂CH₂ radicals in methanol matrix at 87 K. The reaction kinetics are shown to be describable in terms of a time-dependent rate constant k(t). The contribution from the matrix relaxation to k(t) has been determined. The oxidation rate and the shape of the kinetic curve are independent of the type of the radical. Models interpreting the experimental data are discussed.