1,3-Diaryl-2,2-dihaloaziridines in nitration and bromination reactions

In the nitration of 3-(4-nitrophenyl)-1-phenyl-2,2-dichloroaziridine in acetic acid, 1-(o- and p-nitrophenyl)-derivatives are formed in a 35:65 ratio. 1,3-Di-phenyl-2,2-dichloroaziridine undergoes opening of the three-membered ring under the same conditions, forming a mixture of o- and p-nitroanilides and 2-nitro-4-chloroanilides of 2-acetoxy (or 2-chloro)-2-phenylacetic acids. The bromination of 3-(4-nitrophenyl)-1-phenyl-2,2-dichloroaziridine in aqueous acetic acid leads to 1-(4-bromophenyl)-3-(4-nitrophenyl)-2,2-dichloroaziridine, while in a mixture of acetic acid and acetic anhydride it leads to the anilide of 2-bromo-2-phenyl-acetic acid and 2-bromo-N-(2,4-dibromophenyl)-1-(4-nitrophenyl)-2,2-dichloro-ethylamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 912–916, July, 1984.     

Characterization and gas permeability of a three-component polyimide series

Packing density and gas permeability of a three-component copolymide series is presented. The three-component polyimides are prepared a via “stepwise” synthesis procedure that goes through the acid anhydride terminated pre-polymer. The procedure ensures the statistical distribution of segments of the polymers. The polyimide series is composed of contrasting segments: a bulky and rigid hexafluoroisopropylidene-2,2-bis(phthalic acid anhydride)/9,9,-bis(4-aminophenyl)fluorene and a flexible hexafluoroisopropylidene-2-2-bis(phthalic acid anhydride)/2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, with varying segment ratio. Generation of additional free volume by compolymerizing two segments is observed. The permeability of six pure gases—He, H₂, N₂, O₂, CH₄, and CO₂—to the polymides showed positive deviation from the simple additivity rule of segment weight ratio reflecting the generation of free volume. However, a conflicting result between free volume fraction and gas permeability is observed, which may be due to a difference of the nature of free volume of each segment. © 1994 John Wiley & Sons, Inc.     

2-(3-ethyl-2,2-dimethylcyclobutyl-methyl)-4(3H)-quinazolinones

Anthranilic acid and its 5-bromo and 4-chloro derivatives react with pinanoic and pinonoic acid chlorides to give the corresponding N-acyl derivatives. The pinanoyl derivatives give the corresponding 2-(3-ethyl-2,2-dimethyl-cyclobutylmethyl)-4-(3H)-quinazolinones when refluxed in formamide. Pinanoylanthranilic acid reacts with dicyclohexylcarbodiimide to give 2-(3-ethyl-2,2-dimethylcyclobutylmethyl)benz-3,1-oxazin-4(H)-one and subsequently with hydrazine hydrate to give 3-amino-2-(3-ethyl-2,2-dimethylcyclobutylmethyl)-4(3H)-quinazolinone. Refluxing of the pinanoyl- and pinonoylanthranilic acids with acetic anhydride gives acetylanthranilic acid, and pinonoylanthranilic acid gives 4(3H)-quinazolinone with formamide.Riga Technical University, Riga LV-1658, Latvia; e-mail: marina@osi.lanet.lv. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 811–817, June, 1999.     

Synthesis of P,B-containing heterocycles based on bis(α,2-dihydroxybenzyl)phenylphosphine

Conclusions Reaction of bis(,2-dihydroxybenzyl)phenylphosphine and its derivatives with the isobutyl ester of diphenylboric acid, the anhydride of phenylboric acid, and boric acid in the presence of amines forms ammonium 2,8,9-trioxa-1-borata-4-phospha-6,7-benzobicyclo[3.3.1] non-6-enes. Reaction with 2 equivalents of the isobutyl ester of diphenylboric acid gives bis(triethylammonium 2,2-diphenyl-5,6-benzo-1,3,2-dioxaborin-4-yl)phenylphosphine oxide.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 946–951, April, 1989.     

Synthesis of branched polyimides based on 9,9-bis(4-aminophenyl)fluorene and an oligomeric trianhydride,a 1,3,5-triaminotoluene derivative

A new three-arm reactive oligomer (A3) with three end anhydride groups is prepared via the high-temperature cyclocondensation of 1,3,5-triaminotoluene disulfate with excess 2,2-propylidene-bis(phenyl-4-oxyphthalic acid) dianhydride in molten benzoic acid at 140°C in the presence of [2.2.2]-diazobicyclooctane. A branched polyimide is synthesized via the one-step high-temperature catalytic polycondensation of oligomer A3 with 9,9-bis(4-aminophenyl)fluorene in benzoic acid at 140°C via scheme (A3 + B2) and characterized.     

A short approach to chaetomellic anhydride A from 2,2-dichloropalmitic acid: elucidation of the mechanism governing the functional rearrangement of the chlorinated pyrrolidin-2-one intermediate

Chaetomellic anhydride A was efficiently attained in three steps, starting from 2,2-dichloropalmitic acid and 2-(3-chloro-2-propenylamino)pyridine. Atom transfer radical cyclisation selectively formed the cis-stereoisomer of the trichloropyrrolidin-2-one, which underwent a stereospecific functional rearrangement to form a substituted maleimide. The choice of 2-pyridyl, as ‘cyclisation auxiliary’ in the atom transfer radical cyclisation step, proved beneficial for hydrolysis of the maleimide to form the desired anhydride.     

Fluorosulfonyl-containing heterocyclic compounds

When hexafluoroisobutenylidene sulfate is heated above 80°C, hexafluorodimethylketene is liberated and the inner anhydride of hexafluoro--pyrosulfoisobutyric acid (I) is formed. On storage, anhydride I is spontaneously isomerized to hexafluoroisobutenylidene pyrosulfate, which is converted to the mixed anhydride of pentafluoromethacrylic and fluoropyrosulfonic acids on heating above 130° for many hours. On heating above 160°, I is decarboxylated to give hexafluoropropane-2,2-disulfonic acid anhydride, which is inclined to isomerize to pentafluoropropene-2-pyrosulfonyl fluoride.See [1] for Communication IV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No, 10, pp. 1321–1324, October, 1973.     

Polyimides from 4,4′-(alkylene-α,ω-dioxy) bis(phenylsuccinic anhydride)s and bis(phenylglutaric anhydride)s

4,4′-(Alkylene-α,ω-dioxy)bis(phenylsuccinic anhydride)s and bis(glutaric anhydride)s were obtained by the condensation of 4,4′-diformyl-α,ω-diphenoxyalkanes with ethyl cyanoacetate followed by the addition of potassium cyanide or meldrum acid (2,2-dimenthyl-1,3-dioxane-4,6-dione), hydrolysis with concentrated hydrochloric acid, and dehydration with acetic anhydride. Alkylene groups were ethylene, trimethylene, and tetramethylene. Polyimides were prepared from these anhydrides with 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenyl sulfide, and 4,4′-diaminodiphenylmethane through thermal ring closure of polyamic acids obtained by solution polymerization in dimethylacetamide, and thermal stability of these polyimide film was examined by thermogravimetric analysis.     

New energetic polynitro cyclic esters: ammonium, hydrazinium, and hydroxylammonim salts of polynitramines

Reaction of 2,2-dinitro-1,3-propanediol (1) with oxalyl dichloride or malonyl dichloride in refluxing ether led to the formation of cyclic dinitro-containing esters (2, 3) in very good yields. Compounds 2 and 3 were also isolated in similar yields by the treatment of 1 with oxalic acid or malonic acid in trifluoroacetic anhydride at room temperature. Nitration of 3 with fuming nitric acid resulted in the corresponding trinitro cyclic ester 4 in 70% isolated yield. Treatment of 1 with a large excess of methanolic ammonia gave impure 2,2-dinitro-1,3-diaminopropane (5). Polynitraamines, 7 and 11, were treated with aqueous ammonia, hydrazine monohydrate or hydroxylamine in methanol at room temperature to obtain their corresponding salts 8-10 and 12-14, respectively, in excellent isolated yields. All new compounds were characterized by IR, NMR spectroscopy ((1)H, (13)C, (15)N), DSC, and elemental analysis. Their energetic properties, such as impact sensitivity, detonation velocity, and detonation pressure were also determined and compared with existing energetic compounds, such as PETN (pentaerythritol tetranitrate), RDX (1,3,5-trinitro-1,3,5-triazacyclohexane), and TNT (trinitrotoluene).     

Photo-oxidation products of polyetherimide ULTEM determined by MALDI-TOF-MS. Kinetics and mechanisms

Poly 2,2-bis4-(3,4-dicarboxyphenoxy) phenylpropane dianhydride-1,3-phenylendiamine copolymer (ULTEM) was subjected to photo aging in the attempt to find evidence on the structure of the species formed in the oxidative degradation. The oxidation was followed as a function of the exposure time by MALDI and SEC/MALDI techniques. The SEC curves showed extensive degradation, with the formation of low molar mass oligomers having different end groups. Valuable structural information on the photo-oxidized ULTEM species was extracted from the MALDI spectra of the photo-oxidized ULTEM. These showed the presence of polymer chains containing acetophenone, phenyl acetic acid, phenols, benzoic acid, phthalic anhydride and phthalic acid end groups. The mechanisms accounting for the formation of photo-oxidation products involve several simultaneous reactions: (1) photo-cleavage of methyl groups of the N-methyl phthalimide terminal units; (2) photoxidative degradation of the isopropylidene bridge of BPA units; (3) photo-oxidation of phthalimide units to phthalic anhydride end groups: (4) hydrolysis of phthalic anhydride end groups. The kinetic behaviour of all the species detected is in agreement with the predictions of the reaction mechanisms hypothesized.     

THE CONDENSATION REACTION OF BIS(PERFLUOROALKANESULFONYL)METHANES WITH AROMATIC ALDEHYDES

The ccndensation reactions occurred when heating bis(perfluoroalkane-sulfonyl)methanes with aromatic aldehydes in acetic acid anhydrideand gave high yields of 1-aryl-2,2-di(perfluoroalkanesulfonyl)ethylenesThe perfluoroalkanesulfonyl groups R_FSO_2 are known as the strongestelectron-attracting substituents~(1-2).This property is often used in theactivation of C-C multiple and 2,2'-C-H bonds.The synthesis and reactionsof perfluoroalkanesulfonyl substituted alkenes and alkynes are of greatinterest in synthetic organic chemistry~(3-6).Recently,Hanack~7 reported the preparation of 2-aryl-l-(perfluoroalkane-sulfonyl)acrylonitrile R_FSO_2C(CN)=CHAr.However,he failed to obtainthe 1,1-di(perfluoroalkanesulfonyl)alkenes by the Knoevenagel reactionof bis(perfluoroalkanesulfonyl)methane with aldehydes.     

The formation and structure of phenylcamphoric acid and related compounds

The complete structure and stereochemistry of (+)-phenylcamphoric acid has been determined. The acid obtained from the Friedel-Crafts reaction of benzene with isolauronolic acid is identified as (±)-phenylcamphoric acid, α-Campholytic acid is shown to be a likely precursor of phenylcamphoric acid in these reactions. The Friedel-Crafts reaction of 3-cyano-1,2,2-trimethylcyclopentanecarbonyl chloride or 3-cyano-2,2-dimethyl-1-methylenecyclopentane with benzene provides a mixture of phenylcamphornitrile and an isomer. Isofenchocamphoric anhydride similarly provides a mixture of the epimeric 4-phenyl-2,2,4-trimethylcyclopentanecarboxylic acids.     

A new route to (±)-erythro-roccellic acid and chaetomellic anhydride C through functional rearrangement, promoted by n-propylamine or CH3ONa/CH3OH, of N-propyl-3-chloro-4-dichloromethyl-3-dodecylpyrrolidin-2-one

The rearrangement of a trichloro-pyrrolidin-2-one, prepared by the CuCl-TMEDA catalyzed atom transfer radical cyclization of N-alkyl-N-(3-chloro-2-propenyl)-2,2-dichloromyristamide, with n-propylamine or CH₃ONa/CH₃OH, is the key step of a new, short and inexpensive route to chaetomellic anhydride C and (±)-erythro-roccellic acid.     

Thermal and photochemical oxidation of 2-acetylcyclopentanone with atmospheric oxygen

The major products of thermal (acetone, CaCl₂ excess, reflux) and photochemical (acetone or CCl₄, room temperature) oxidation of 2-acetylcyclopentanone with atmospheric oxygen are 2-acetyl-2-hydroxycyclopentanone, 2-acetyl-2-hydroxymethylcyclopentanone, 1,1′-diacetyl-1,1′-bicyclopentyl-2,2′-dione, 2-acetoxycyclopentanone, 5,6-dioxoheptanoic acid, glutaric acid, and glutaric anhydride. The formation of 2-acetyl-2-hydroxycyclopentanone is the first example of the direct α-hydroxylation of β-dicarbonyl compound under the conditions described.     

Metallacycloalkanes : II. Reactions of α,α′-bipyridyl-5-nickela-3,3,7,7-tetramethyl-trans-tricyclo[4.1.0.02,4]heptane

The title compound (II) underwent reductive elimination on treatment with maleic anhydride, tetracyanoethylene or triphenylphosphite to give 3,3,6,6,-tetramethyl-trans-tricyclo[3.1.0.0^2,4]hexane (III). With triphenylphosphite bi(2,2-dimethylcyclopropyl) (V) and 1-(2,2-dimethylcyclopropyl)-3-methyl-1,3-butadiene (VI) were also formed. Acidolysis of II with either HCl, malonic acid or methanol gave V. An intermediate complex α,α′-bipyridyl(phenoxy)-3-nickel-1,1′-bi-(2,2′-dimethylcyclopropyl) (VIII) was isolated by reaction of II with phenol. Methylene dibromide reacts with II to give III and 3,3,7,7-tetramethyl-trans-tricyclo[4.1.0.0^2,4]heptane (IV). With triethylaluminum and II complete exchange of the alkyl groups occurred and V was released on hydrolysis. Trifluoroborane diethyl ether and II gave 3,3,6,6-tetramethylcyclohexa-1,4-diene in a rearrangement-displacement reaction. The cyclodimerisation of 3,3-dimethylcyclopropene (I) to III catalysed by II and the fact that II can be recovered from the reaction mixture provides strong evidence for the intermediacy of metallacyclopentanes in these transition-metal-catalysed [2π + 2π] cyclo-additions.     

On the formation and solvolysis of 4-aryl-2,2-difluoro-6-methyl-1,3,2-(2H)-dioxaborines

The condensation of aryl methyl ketones 6 with acetic anhydride 4a in the presence of the boron trifluoride-acetic acid adduct 7 gives rise to the formation of 4-aryl-2,2-difluoro-6-methyl-1,3,2-(2H)-dioxaborines 8 in satisfactory yields. The stable 4-aryl-2,2-difluoro-6-methyl-1,3,2-(2H)-dioxaborines 8 can be transformed by hydrolysis into the corresponding aroylacetones 9. The reaction was optimized so as to avoid the formation of by-products, such as 2,4-diaryl-6-methylpyrylium tetrafluoroborates 11 or self-condensation products. © 1997 John Wiley & Sons, Inc.     

Über die reaktion von pyridin mit maleinsäureanhydrid-I

The reaction between pyridine and maleic anhydride was studied thermoanalytically. With reagents of high purity, the reaction proceeds very slowly with formation of oligomeric and polymeric products. Protic reagents (such as water, maleic acid, acetic acid or pyridinium hydrochloride) catalyse the reaction during which polymerization occurs at a later stage.Radical inhibitors (such as sulphur, 2,2-diphenyl-1-picryl hydrazyl or anthracene) have no influence on the reaction rate.Ultra-violet spectroscopic studies on solutions of maleic anhydride and some derivatives in pyridine and dimethyl sulphoxide show a charge-transfer absorption for the maleic anhydride/pyridine system at 303 nm.     

Coulometric generation of acetylions by oxidation of mercury in acetic anhydride and in acetic acid/acetic anhydride mixture

Coulometric generation of acetyl (CH₃CO⁺) ions by oxidation of mercury in acetic anhydride and in acetic acid/acetic anhydride (5:95, v/v) is described. Current/potential curves for solvents, titrated bases, indicator and mercury showed that in both these solvents mercury is oxidized at potentials which are much more negative than those for the titrated bases and other components present in the solution. Quinoline, triethanolamine, triethylamine, pyridine and quinolin-8-ol in acetic anhydride, as well as triethylamine, 2,2′-bipyridine, 2,4,6-collidine, pyridine and sodium acetate in acetic acid/acetic anhydride were titrated with acetyl ions generated by the oxidation of mercury. In this way, it was established that the oxidation of mercury to mercury (I) ions proceeds quantitatively with 100% current efficiency.     

Synthesis of 4H-1,3,4-oxadiazino[5,6-b]quinoxalines from 2-substituted quinoxaline 4-oxides

The reaction of 6-chloro-2-(1-methylhydrazino)quinoxaline 4-oxide 8 with acetic anhydride resulted in the intramolecular cyclization to give 8-chloro-2,4-dimethyl-4H-1,3,4-oxadiazino[5,6-b]quinoxaline 7a , while the reaction of compound 8 with acetic anhydride/pyridine or acetic anhydride/acetic acid afforded 3-(2,2-diacetyl-1-memymydrazmo)-7-chloro-2-oxo-1,2-dihydroquinoxaline 9 , effecting no intramolecular cyclization. The reaction of 2-(2-acetyl-1-methylhydrazino)-6-chloroquinoxaline 4-oxide 10a or 6-chloro-2-(1-methyl-2-trifluoroacetylhydrazino)quinoxaline 4-oxide 10b with phosphoryl chloride provided compound 7a or 8-chloro-4-memyl-2-trifluoromethyl-4H-1,3,4-oxadiazino[5,6-b]quinoxaline 7b , respectively. The reaction of compound 7b with phosphorus pentasulfide gave 7-chloro-3-(1-methyl-2-trifluoroacetylhydrazino)-2-thioxo-1,2-dihydroquinoxaline 11 , whose dehydration with sulfuric acid in acetic acid afforded 8-chloro-4-methyl-2-trifluoromemyl-4H-1,3,4-thiadiazino[5,6-b]quinoxaline 12 .     

Synthesis and cytotoxic activity of 11-nitro and 11-amino derivatives of acronycine and 6-demethoxyacronycine

Condensation of 2-chloro-3-nitrobenzoic acid with either 5-amino-7-methoxy-2,2-dimethyl-2H-chromene or 5-amino-2,2-dimethyl-2H-chromene afforded diphenylamines 14 and 15. Trifluoroacetic anhydride mediated cyclization gave the corresponding acridones 16 and 17, which were subsequently N-methylated and reduced to 11-aminoacronycine and 11-amino-6-demethoxyacronycine. These two amino compounds, which gave stable water soluble salts, were 2- to 3-fold more potent than acronycine or 6-demethoxyacronycine in inhibiting L1210 cell proliferation.