Acetic Anhydride Solution Research Articles

Medium-sized cyclophanes. Part 31. Synthesis and electrophilic substitution of 8-substituted [2]metacyclo[2](1,3)pyrenophanes

syn- and anti-2,11-Dithia[3] metacyclo[3](1,3) pyrenophanes 15 have been obtained by coupling the corresponding 1,3-bis(bromomethyl)pyrene 11 and 1,3-bis(mercaptomethyl)benzenes 14 in ethanol under high-dilution conditions. Oxidation of the obtained thiametacyclophanes 15 with m-chloroperbenzoic acid afforded the corresponding syn- and anti-disulfones 18. Pyrolysis of the syn- and anti-disulfones 18 afforded exclusively the corresponding anti-[2]metacyclo[2](1,3)pyrenophane 19 in 40–70% yield along with the ring-cleavage product, 7-tert-butyl-1,3-dimethylpyrene 8. The nitration of 5,15-di-tert-butyl-8-methyl-19b and 5,15-di-tert-butyl-8-methoxy-[2]metacyclo[2](1,3)pyrenophane 19d with 1 mol equiv. of copper(II) nitrate in acetic anhydride solution exclusively occurred on the more reactive pyrene ring to afford 14-nitro derivatives 21a and 21b in 83 and 86% yield, respectively. On the other hand, the bromination of substrates 19 with bromide in methylene dichloride solution afforded 13-bromo derivatives 23 along with the transannular cyclization products 24 and 25. These different orientations for the electrophilic substitution are also discussed.

Comparison of behavior in muscle fiber regeneration after bupivacaine hydrochloride- and acid anhydride-induced myonecrosis

We compared the morphologic characteristics of muscle fiber necrosis and subsequent regeneration after injury induced by intramuscular injections of bupivacaine hydrochloride (BPVC) and a variety of solutions at acid and alkaline pH (acetic anhydride, citric acid buffer, and sodium carbonate buffer). After BPVC injection the necrotic muscle fibers were rapidly invaded by phagocytic cells, followed by active regeneration and very little fibrous scar formation. The regenerating muscle fibers increased rapidly in size and attained complete fiber type differentiation and regained their initial fiber diameter within 1 month. Both alkaline and acid solutions induced muscle fiber necrosis followed by regeneration. Fiber necrosis induced by alkaline buffers and acetic anhydride solutions above pH 5.0 produced changes quite similar to that induced by BPVC. However, injection with 0.1 M acetic anhydride at pH below 4.0 resulted in coagulative necrosis of the injured muscle with very little phagocytic infiltration with poor regenerative activity and dense fibrous tissue scarring. Thus, pH 4.0 appears to be the critical pH determining the type of muscle injury and subsequent poor phagocytic and regenerative activities. This model of acidic acetic anhydride injury may lead to the identification of factors which interfere with regeneration and cause fibrous tissue scarring in human muscular dystrophy.

1‐acetoxyvinyl phosphonates: Facile synthesis via catalytic acylation of dialkyl phosphites

AbstractA new and facile method of synthesis of 1‐acetoxyvinyl phosphonates (2) has been found. Dialkyl phosphites react readily with acetic anhydride in acetonitrile solution in the presence of catalysts to produce 2 and acylphosphonates (1) as a minor product. The most efficient catalysts are metal compounds of variable valency: iron(II), iron(III), and cobalt(II) chlorides. The same compounds catalyze transformation of 1 into 2 in an acetonitrile solution of acetic anhydride.

Additive Pummerer reactions of vinylic sulphoxides. Synthesis of 2-(phenylsulphenyl) aldehydes and primary alcohols

Reaction in acetic anhydride solution of α,β-unsaturated sulphoxides 1 with sodium acetate and triflic anhydride gives 2-(phenylsulphenyl) acylals 4. Basic methanolysis of 4 gives 2-(phenylsulphenyl) aldehydes 8, whilst reduction gives directly 2-(phenylsulphenyl) primary alcohols 9.

特集「高機能両親媒性化合物の合成とその高次構造」 ポリイミド前駆体ＬＢ膜の累積挙動とそのイミド化過程の水晶振動子マイクロバランス法による研究

The processes of deposition of precursor LB films and imidization to polyimide LB films were monitored by weight change using a piezoelectric quartz plate as a microbalance. N-Octadecylpyrrolidine was better than N, N-dimethyloctadecylamine as a long alkyl amine to obtain the Y-type multilayer. Although imidizaion using the solution of acetic anhydride and pyridine was performed within several hyndred seconds in benzene, it did not complete in hexane, whereas initial imidization speed was faster in hexane. Swelling would be important factor for imidization process, because benzene make the LB film swell more than other solvents.

Dienone–phenol rearrangement mechanism of 8,8-dimethyl- and 6,8,8-trimethyl-naphthalene-1,4,5(8H)-triones in acetic anhydride solution

Dienone–phenol rearrangement of 8,8-dimethyl- and 6,8,8-trimethyl-naphthalene-1,4,5(8H)-triones (1) and (2) in acetic anhydride as solvent is the subject of a kinetic study. The effects of sulphuric and acetic acids are also investigated. Both substrates show limiting [H2SO4] dependence and an inhibiting effect with acetic acid. The effect of temperature in the reaction of (1) and that of the C-6 methyl group of (2) are discussed. The results are rationalized in terms of the formation of acylated intermediate cations and schematic representation is provided.

Reactions of the radial cattions of acetic acid and acetic anhydride in CFCl3

The ESR spectra of γ-irradiated, at −196 °C, solutions of acetic acid and acetic anhydride were studied depending on their concentrations in CFCl3. The structure of thus produced radical cations is confirmed with the deuterium substituted analogues. It has been shown that the ion-molecular reaction of the radical cation CH2COOH+ in the isolated dimer takes place for the dilute solutions of acetic acid in CFCl3 resulting in the formation of CH3COO follwed by its decomposition to CH3+CO2 while the radicals CH2COOH are formed via secondary processes. The reactions of radical cations of acetic oxide have been also studied.

Synthesis, reactions and characterisation of some new β-ketoester boroacetates

The reactions of methyl esters of aroyl pyruvic acids (aroyl = benzoyl,p-chlorobenzoyl,p-bromobenzoyl andp-methylbenzoyl) with boric acid in acetic anhydride solution yield derivatives of the general formula (OAc)2B [OC(R)CHCOCOOMe] (R = C6H5,p-ClC6H4,p-BrC6H4 andp-CH3C6H4). The reactions of these derivatives with protic ligands such as glycols,o-aminophenol ando-aminothiophenol have also been carried out. These derivatives have been characterised by elemental analysis and molecular weight measurements. The tetra-coordination around central boron atom has been established byir,1Hnmr and 11 Bnmr spectral evidence.

Nitration in the carbazole series

Nitration of9-tosylcarbazole in acetic anhydride solution gives l-nitro (28%), 2-nitro (19%) and 3-nitro (53%) derivatives. The mixture of the nitro compounds obtained from 9-acetylcarbazole contains 10%, 48% and 42% of the isomers, respectively. Under similar conditions 9-nitrosocarbazole shows a different isomer distribution: 34% of 1-nitro and 66% of 3-nitrocarbazole. Nitration of carbazole is a two step process involving formation and rearrangement of 9-nitrocarbazole. The hypothesis was supported by the results of 1,3,6,8-tetrachlorocarbazole nitration and oxidation of 9-nitrosocarbazole and rearrangement of 9-nitrocarbazole in the nitration conditions.

Emission spectra from copper proteins containing type-3 centres.

Aqueous solutions of copper-proteins containing type-3 centres (ceruloplasmin, tyrosinase, haemocyanin), excited within their absorption bands at 325-345 nm, show typical luminescence spectra. The emission bands peak at 415-445 nm and their decay time is no longer than 10 ns. A strong analogous fluorescence is obtained also by excitation of concentrated solutions of carboxylic acids and amino acids, which show again absorption bands around 330 nm. Such a fluorescence, although less intense, is also observed in copper(II) carboxylate solutions. In contrast, no fluorescence has been recorded in solutions of acetic anhydride and of polypeptides (valinomycin, gramicidin D), which do not have free carboxyl groups. We tentatively attribute this novel fluorescence in the investigated copper proteins to interactions between carboxyl groups of amino acids at, or near, the active site.

Determination of tertiary aliphatic amines by high-performance liquid chromatography

A high-performance liquid chromatographic method using on-line derivatization is described for the determination of tertiary aliphatic amines. The amines are separated on a column packed with Nucleosil 5N(CH 3) 2 resin, and are detected by post-column derivatization based on a reaction with a colour reagent consisting of an acetic anhydride solution of citric acid. The reaction, which gives a wine red colour, is specific and primary and secondary amines do not react or interfere. The calibration graph is linear over the range 0.05–0.5% for aliphatic mono-, di- and trialkylamines and lower limit of determination is 0.01%.

A solid sorbent air sampling method for O-phenylenediamine (OPD)

A method for collecting, storing and quantifying airborne vapors of O-phenylenediamine (OPD) in the workplace has been developed. The vapors are collected on 100 mg of Tenax-GC packed in 4 mm ID glass tubing wrapped with aluminum foil. The OPD is desorbed and derivatized using a 10% solution of acetic anhydride in acetonitrile to form diacetamidobenzene (DAAB). The DAAB was subsequently quantified by injecting 10 µL of the solution into a liquid chromatograph equipped with a UV-detector (254 nm), a Partisil PXS PAC column and a 7% methanol in 1-chlorobutane mobile phase. The limit of detection is approximately 10 ng. Samples collected from test atmospheres containing OPD in dry air at concentrations ranging from 0.05 to 0.2 mg/m3 gave an overall recovery of 86.6%. Recoveries of samples collected from atmospheres humidified to 80% relative humidity were 79%. The capacity of the tube is at least 25 µg which is sufficient for either short or long term samples.

The development of an air sampling and analytic method for o-phenylenediamine in an industrial environment.

A new method for monitoring o-phenylenediamine (OPD) in the industrial environment was developed. Some aromatic amines such as OPD are difficult to collect and analyze directly because they are sensitive to oxidation. The method developed overcomes this difficulty by derivatizing the OPD directly upon collection. The OPD vapor is drawn through a bubbler containing acetic anhydride to form the relatively stable 1,2-diacetamidobenzene. The acetic anhydride solution is analyzed by means of high performance liquid chromatography (HPLC), and the diacetamido derivative quantified. The analysis is linear for standard solutions in the range of 0.5 microgram/mL to over 0.5 mg/mL. Air concentrations of OPD were prepared by passing a metered stream of nitrogen through a class tube packed with OPD crystals and diluting the stream with a metered air stream to achieve the desired level. The collection efficiency and conversion of OPD to the derivative was found to approach 100% at vapor concentrations of 0.09 mg/m3 but was reduced to about 60% at 0.02 mg/m3. The poor recovery at low concentrations appeared to be at least in part due to wall adsorption. Moisture had little effect on sample collection and analysis. O-Toluenediamine, chemically similar to OPD, was found to interfere in the analysis.

パルプ・紙化へのガンマ線照射の影響 ＩＩＩ パルプへのガンマ線照射

The dissolving pulp (DP) involving no lignin and the cold soda pulp involving much amounts of lignin were used in order to study the influence of gamma irradiation.The experimentals were carried out in the presence of air (dryed state), in the water, methanol, acetic anhydride, acetic anhydride+methanol, dioxane, dimethyl sulfoxide and 1% NaOH solution as deaerated as possible from each solutions. The irradiation was for 100 hours at the temperature of 2021°C. Total irradiation dose was 1.47 × 107 R.The yields, lignin content, 1 % NaOH solubility, and then brightness were determined. In the case of acetic anhydride and the mixing solution of acetic anhydride and methanol the degree of acetylation also was determined.The following results were obtained from the above-mentioned experiments.1) Yield and analytical valueIn the case of dimethyl sulfoxide which is a good solubilizer for pulp as well as especially in the case of 1% NaOH solution, the yield decreased by the irradiation.It was found that this phenomenon was denoted remarkably for the cold soda pulp.2) For the pulp immersed in the water the brightness of pulp was not pratically improved by the irradiation, but relatively remarkably improved for immersing in methanol. Thus phenomenon was observed in both DP and the cold soda pulp. The improvement of the degree of brightness is not the change in quality of lignin, but it may be considered reasonably to take place by the action of oxidizing bleach with a smaller amount of oxygen of air remaining in the material. And also by comparison with immersing in water, it is considered for immersing in methanol that the action of bleaching arises from the presence of an extremely small amount of oxygen. Additionally, 1% NaOH solubility gets a small value in the both systems. Therefore, it may be considered that the degree of brightness is improved by the oxidation reaction, but the degradation degree of pulp gives a small value.3) From the scope of results obtained by the infrared analysis. it seems most reasonable to conclude that methanol does not react with lignin in the cold soda pulp even on irradiating.4) In practice, it was found that the acetylation was accelerated by the gamma-rays irradiation.

Cyclization of Isothiosemicarbazones. I. A New Route to 2-Mercapto-imidazole Derivatives and 4-Substituted Imidazoles

Abstract Some 1-arylmethyleneamino-2-mercapto-4-aryl-1H-imidazole derivatives were prepared by the condensation of isothiosemicarbazones of aromatic carbonyl compounds with phenacyl bromides. The 1,2,5-trisubstituted isomers were obtained by substitution of dl-α-bromophenylacetaldehyde for phenacyl bromide in this condensation. The reaction of isothiosemicarbazones of aliphatic carbonyl compounds with phenacyl bromides produced a dark, complex mixture from which the corresponding 1-alkylideneamino-2-mercapto-4-aryl-1H-imidazoles and 3,5-disubstituted 1,2,4-triazines were isolated in poor yields, with the latter being a main product or a sole heterocyclic product depending on the reaction conditions. Reductive cleavage of the cyclized products with zinc dust in acetic acid-acetic anhydride solution gave 1-acetyl-4-aryl-1H-imidazoles, which were readily hydrolyzed to 4-aryl-1H-imidazoles. The susceptibility to acid hydrolysis of the arylmethyleneamino group was dependent on the extent of conjugation between the azomethine double bond and the adjacent aromatic rings. Hydrazinolysis of the azomethine double bond yielded 1-amino-2-mercapto-4-aryl-1H-imidazoles in high yields. Their structures were established on the basis of NMR, IR, UV, and mass spectra as well as elemental analyses. Differentiation between 1,2,4- and 1,2,5-trisubstituted imidazoles was discussed.

5-thio- l-rhamnose

Two routes for the synthesis of methyl 5- S-acetyl-6-deoxy-2,3- O-isopropylidene-5-thio- l-mannofuranoside (8) have been examined. Reaction of l-rhamnose with methanol in the presence of the cation-exchange resin gives methyl 6-deoxy-α- l-mannofuranoside (2), which on conventional acetonation yields methyl 6-deoxy-2,3- O- isopropylidene-α- l-mannofuranosides (3). Compounds 3 is also obtained by acetonation of l-rhamnose followed by treatment with a mixture of methanol, acetonation, Amberlite IR-120(H +) resin. Chlorination of 3 with triphenylphosphine-carbon tetrachloride gives methyl 5-chloro-5,6-dideoxy-2,3- O-isopropylidene-β- d-gulofuranoside (7), which reacts with potassium thioacetate to give 8. Alternatively, 3 is iodized with ruthenium tetraoxide to methyl 6-deoxy-2,3- O-isopropylidene-α- l- lyxo-hexofuranosid-5-ulose (9), which reduced by sodium borohydride mainly to methyl 6-deoxy-2,3- O-isopropylidene-β- d-gulofuranoside (10). The O-tosyl derivative of 10 reacts with potassium thioacetate to produced 8. Hydrolysis of 8 with 90% aqueous triflouroacetic acid, followed by acetolysis with a solution of acetic acid, acetic anhydride, and sulfuric acids gives an anomeric mixture of 1,2,3,4,-tetra- O-acetyl-6-deoxy-5-thio- l-mannopyranoses (12), together with a small proportion of 1,2,3,-tri- O-acetyl-5- S-acetyl-6-deoxy-5-thio-β- l-mannofuranose (13). Deacetylation of 12 or 13 gives 5-thio- l-rhamnose (6), from which crystalline 1,2,3,4-tetra- O-( p-nitrobenzoyl)-5-thio-β- l-rhamnopyranose (14) is obtained.

Purines, pyrimidines, and imidazoles. Part XLIV. Syntheses of some dihydro-1,3-oxazine derivatives and related substituted uracils

6-Methyl-1,3-oxazine-2,4(3H)-dione has been prepared from ethyl acetoacetate by reaction with NN-dimethyl- or NN-diethyl-urea in acetic acid–acetic anhydride solution, and by heating with ethyl carbamate in the presence or absence of solvent. The oxazinedione was also produced by heating ethyl N-acetoacetylcarbamate, and by heating N′-acetoacetyl-NN-dimethylurea with acetic acid–acetic anhydride or sulphuric acid. The compound was identical with material prepared from diketen and NN-dimethylurea, and its structure was confirmed by 1H and 13C n.m.r. spectroscopy. Similar reactions of various β-oxo-esters, including C-methyl and C-benzyl derivatives, with ethyl carbamate and with NN-dimethylurea provided various 6-aryl- and 6-alkyl-oxazinediones and 5,6-dialkyloxazinediones. Treatment of the oxazinediones and their N-alkyl derivatives with ammonia and with primary amines gave substituted uracils and with secondary amines, acylated ureas. The 6-methyloxazinedione dimerised when heated with sodium hydroxide to give (6-hydroxy-4-methyl-2-pyridyl)acetic acid.

A NEW SYNTHETIC PROCEDURE OF N-(2-HYDROXYETHYL)ETHYLENEDIAMINETRIACETATOMANGANESE(III) COMPLEX

Abstract When manganese(III) acetate was mixed with Na3hedtra in an acetic anhydride solution, Na[Mn(hedtra)(CH3COO)]·H2O·1/2(CH3CO)2O complex was obtained. This complex was unstable in an aqueous solution, but fairly stable in non-aqueous solvents such as methyl alcohol and dimethyl sulfoxide. This preparative method may be useful to synthesize other manganese(III) complexes.

Acyloxy neighboring-group participation in the acid-catalyzed cleavage of methyl 2,3-anhydro-β- d-ribofuranoside

The reaction of methyl 2,3-anhydro-β- d-ribofuranoside with hydrogen bromide in an acetic acid—acetic anhydride solution leads to the formation of methyl 2,3-di- O-acetyl-5-bromo -5-deoxy-α,gb- d-xylofuranoside. Similar treatment of methyl 2,3-anhydro-5- O-benzoyl-β- d-ribofuranoside provided methyl 2- O-acetyl-3- O-benzoyl-5-bromo-5-deoxy-α,β- d-xylofuranosides. The position of halogen substitution was ascertained by hydrogenolysis to the resultant 5-deoxy sugars, which were characterized by their n.m.r. spectra. Confirmation of the structural assignment for methyl 2- O-acetyl-3- O-benzoyl-5-deoxy-α,β- d-xylofuranoside was obtained by synthesis from 1,2- O-isopropylidene-α- d-xylofuranose. The formation of the 5-bromo derivatives under the reported conditions probably occurred through the intermediacy of the 3,5-acyloxonium ions. Similar conversions were observed when the starting compound was treated with hydrogen chloride, acetyl bromide, or acetyl chloride in acetic acid—acetic anhydride solutions.

ChemInform Abstract: NEW SYNTHESES OF SOME 1,3‐OXAZINE DERIVATIVES

AbstractDiketen (I) und der Dimethylharnstoff (II) bilden das 1,3‐Oxazin (III), dessen Methylderivat (IV) mit Aminen zu den Pyrimidindionen (V) reagiert.