Reactions of lycoctonine alkaloids with acetic anhydride and p-toluenesulfonic acid

The reactions of alkaloids having a 7,8-diol system — lycoctonine, browniine, and dihydromonticoline — with acetic anhydride and p-toluenesulfonic acid have been studied. The optimum conditions for this reaction, leading to anhydro compounds, have been found.Abuali ibn Sino [Avicenna] Tadzhik State Medical Institute, Dushanbe; Institute of Chemistry, Baskir Scientific Center, Urals Branch, Academy of Sciences of the USSR, Ufa. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 545–547, July–August, 1991.     

Reactions of lycoctonine alkaloids with acetic anhydride and p-toluenesulfonic acid

The reactions of alkaloids having a 7,8-diol system — lycoctonine, browniine, and dihydromonticoline — with acetic anhydride and p-toluenesulfonic acid have been studied. The optimum conditions for this reaction, leading to anhydro compounds, have been found.     

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.     

Multiphase telomerisation of butadiene with acetic acid and acetic anhydride

Two different routes to acetoxyoctadiene are presented. The first one uses the well-known telomerisation of butadiene with acetic acid operating in a multiphase semi-batch mode. The second reaction involves the cleavage of acetic anhydride, hydrogen transfer via ketene formation and thus a telomerisation as well.     

Reactions of the monoxides of 2,6-disubstituted pyrazines with phosphoryl chloride and acetic anhydride

The monoxides of 2, 6-dimethyl-( 1 ), 2, 6-diphenyl-( 2 ), and 2-methyl-6-phenylpyrazines ( 3 ) were subjected to the reactions with phosphoryl chloride and acetic anhydride. Some reactions of the chloropyrazines and hydroxypyrazines obtained thus were also investigated.     

Potentiometric determination of urea with perchloric acid in acetic anhydride

A potentiometric method for the quantitative determination of urea is proposed. Urea is titrated with perchloric acid in acetic anhydride solvent. This method is rapid and less costly than the semi-micro Kjeldahl method. In addition, its accuracy is nearly identical with that of Kjeldahl's method. An analysis of a given sample is completed in about 30 min.     

The rearrangement polymerization of phosphorous acid with acetic anhydride

Phosphorous acid reacts with acetic anhydride to give almost quantitative yields of poly(ethane,1-hydroxy,1,1-diphosphonates); hydrolysis studies suggest the presence of the interlinked units

in the product.     

Studies on tertiary amine oxides. LXVII . Reactions of aromatic N-oxides with 3-arylrhodanines in the presence of acetic anhydride

Quinoline 1-oxides 1 readily react with 3-arylrhodanines 2 in the presence of acetic anhydride to afford 3-aryl-5-(2-quinolyl)rhodanines 3 in high yields. These products resist hydrolysis under both alkaline and acidic conditions, but is oxidized to quinaldinic acid 1-oxide 4 with 30% hydrogen peroxide in hot acetic acid. Besides isoquinoline 2-oxide 5 , pyridine 1-oxide 7a also reacts in the same way to give 3-aryl-5-(2-pyridyl)rhodanines 8 , although the reactivity of γ-picoline 1-oxide 7b is considerably lower. Contrary to 3 , 3-phenyl-5-(2-pyridyl)rhodanine 8a is successfully hydrolyzed with boiling 48% hydrobromic acid to 2-pyridinemethanethiol 10 in 57% yield.     

C- and N-cyanoacetylation of 6-aminopyrimidines with cyanoacetic acid and acetic anhydride

A series of 6-aminopyrimidines are cyanoacetylated with a mixture of cyanoacetic acid and acetic anhydride. When pyrimidin-4(3H)-ones are used as substrates, the substitution occurs at C-5, however, when the substrates are substituted pyrimidines at the C-2 and C-4, the cyanoacetylation takes place at the exocyclic amino group.     

New possibilities in nitration with a mixture of nitric acid and acetic anhydride

Summary A mixture of nitric acid and acetic anhydride with a nitric acid content of 80 moles per cent has a considerably more powerful nitrating action than a mixture with 35–50 moles per cent of nitric acid. It is desirable to use this mixture for the nitration of furans with low sensitivity to electrophilic attack.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 103–110, January, 1965     

Bromination of isoprene in acetic anhydride

Conclusions The reaction of bromine with isoprene in acetic anhydride as the medium proceeds as competing brominnation and bromoacetoxylation.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1675–1677, July, 1977.     

COMMUNICATION: Mild reaction of ethyl cellulose and N- phenylmaleamic acid in acetic anhydride

The reaction at room temperature of ethyl cellulose (EC) and N-phenylmaleamic acid (NPMA) (maleanilic acid) in acetic anhydride with a catalytic amount of anhydrous sodium acetate resulted in a Michael type of product whereby a cellulose ether was formed. The cyclisation product N-phenylmaleimide was minor. This revised version was published online in August 2006 with corrections to the Cover Date.     

Synthesis of 2-oxo and 2-thioxo-3(2H)-benzothiazoleethanimic acid anhydride with acetic acid and related products

The reaction of the appropriate 2-benzothiazolinone with 2-chloroacetamide under basic conditions afforded the 2-oxo-3(2H)-benzothiazolineacetamides 6–9. The 2-thioxo-3(2H)-benzothiazolineacetamide ( 10 ) was prepared by the reaction of 3-(carbethoxymethyl)benzothiazoline-2-thione with ammonium hydroxide. The reaction of acetamides 6–10 with the appropriate anhydride containing a catalytic amount of the sodium salt of the acid corresponding to the anhydride afforded the titled compounds 11–18 in excellent yields. The omission of the catalyst in the same reaction furnished a mixture containing 57% of the titled compound, 37% of the nitrile and 6% of an unknown. Possible mechanism and supporting nmr, ir and mass spectral data are discussed.     

Kinetics and mechanism of the cleavage of phthalic anhydride in glacial acetic acid solvent containing aniline

Apparent second-order rate constants (k(n)(app)) for the nucleophilic reaction of aniline (Ani) with phthalic anhydride (PAn) vary from 6.30 to 7.56 M(-1) s(-1) with the increase of temperature from 30 to 50 degrees C in pure glacial acetic acid (AcOH). However, the values of pseudo-first-order rate constants (k(s)) for the acetolysis of PAn in pure AcOH increase from 16.5 x 10(-4) to 10.7 x 10(-3) s(-1) with the increase of temperature from 30 to 50 degrees C. The values of k(n)(app) and k(s) vary from 5.84 to 7.56 M(-1) s(-1) and from 35.1 x 10(-4) to 12.4 x 10(-4) s(-1), respectively, with the increase of CH(3)CN content from 1% to 80% v/v in mixed AcOH solvents at 35 degrees C. The plot of k(s) versus CH(3)CN content shows a minimum (with 10(4) k(s) = 4.40 s(-1)) at 50% v/v CH(3)CN. Similarly, the variations of k(n)(app) and k(s) with the increasing content of tetrahydrofuran (THF) in mixed AcOH solvent reveal respective a maximum (with k(n)(app) = 17.5-15.6 M(-1) s(-1)) at 40-60% v/v THF and a minimum (with k(s) = approximately 0-1.2 x 10(-4) s (-1)) at 60-70% v/v THF. The respective values of DeltaH* and DeltaS* are 15.3 +/- 1.2 kcal mol(-1) and -20.1 +/- 3.8 cal K(-1) mol(-1) for k(s) and 1.1 +/- 0.5 kcal mol(-1) and -51.2 +/- 1.7 cal K(-1) mol(-1) for k(n)(app), while the values of k(n) (= k(n)(app)/f(b) with f(b) representing the fraction of free aniline base) are almost independent of temperature within the range 30-50 degrees C. A spectrophotometric approach has been described to determine f(b) in AcOH as well as mixed AcOH-CH(3)CN and AcOH-THF solvents. Thus, the observed data, obtained under different reaction conditions, have been explained quantitatively. An optimum reaction condition, within the domain of present reaction conditions, has been suggested for the maximum yield of the desired product, N-phenylphthalamic acid.     

Acylation of 2,4-diaryl-4H-chromenes by the action of acetic anhydride and perchloric acid

4H-Chromenes were found to be acylated at the 3-position by the action of acetic anhydride and perchloric acid. The structure was determined of other reaction products — the indenobenzopyrylium and 2,4-diaryl-1-benzopyrylium salts.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1042–1046, August, 1990.