Manganese-mediated acetylation of alcohols,phenols, thiols,and amines utilizing acetic anhydride

Manganese(II) chloride-catalyzed acetylation of alcohols, phenols thiols and amines with acetic anhydride is reported. This method is environment-friendly and economically viable as it involves inexpensive, relatively benign catalyst, mild reaction condition, and simple workup. Acetylation is performed under the solvent-free condition at ambient temperature and acetylated products obtained in good to excellent yields. Primary, secondary heterocyclic amines, and phenols with various functional groups are smoothly acetylated in good yields. This method exhibits exquisite chemoselectivity, the amino group is preferentially acetylated in the presence of a hydroxyl/thiol group.     

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.     

Cleavages of ethers by chlorotrimethylsilane and acetic anhydride

Methyl and benzyl ethers have been cleaved with a combination of reagents consisting of chlorotrimethylsilane and acetic anhydride containing a catalytic amount of concentrated sulfuric acid. Methylthiomethyl ethers yield the corresponding acetoxymethyl ethers with chlorotrimethylsilane and acetic anhydride. Comparative study with the borontrifluoride etherate and acetic anhydride method of ether cleavage suggests that chlorotrimethylsilane and acetic anhydride (con. H₂SO₄ catalysis) could be a useful alternative to it.     

The action of acetic anhydride on N-methyltryptophans

Summary A new furocoumarin of composition C₂₁H₂₂O₇ has been isolated from the fruit ofLibanotis transcaucasica Schischk. It has been established that libanotin is a derivative of 8-isopropyloxy-8,9-dihydroangelicin. The side groups of libanotin — acetic and 2-methyl-cis-crotonic acids — are attached to the main part of the molecule by ester bonds.Khimiya Prirodnykh Soedinenii, Vol. 1, No. 3, pp. 215–220, 1965     

Reaction of hexafluoroacetone with acetic anhydride

Conclusions When acetic anhydride reacts with hexafluoroacetone it acts not as an acetylating agent, but as a compound containing an active methylene group.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1661–1662, September, 1966.     

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.     

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.     

The formation of symmetrical diaminoketones by the action of acetic anhydride on acetyl-N-methylamino acids

Summary When acetyl-N-methylamino acids are heated with acetic anhydride, bis-acetyl derivatives of N,N-dimethyl-, -diaminoketones are formed.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 5, pp. 344–348, 1966     

Efficient deanilidation of phosphoranilidates by the use of nitrites and acetic anhydride

Reagent systems of sodium– and tetrabutylammonium nitrite–acetic anhydride were proved to be extremely efficient for the deanilidation of nucleoside 3′-phosphoranilidates, whose reactions were rapid with the former and instant with the latter. It was further found that the reagent system is applicable to oligonucleotide synthesis provided that the exocyclic amino groups of 2′-deoxyadenosine, 2′-deoxyguanosine, and 2′-deoxycytidine were protected by succinylation.     

Preparation and characterization of Zr-MCM-41 synthesized under microwave irradiation condition for acetylation of 1,2-dimethoxybenzene with acetic anhydride

The liquid phase of acetylation of 1,2-dimethoxybenzene with acetic anhydride has been investigated over a series of acid zirconium mesoporous materials (Zr-MCM-41) synthesized by a microwave irradiation method with different Si/Zr ratios (Si/Zr?=?90, 60, 10) and characterized by several spectroscopic techniques such as: N₂ physical adsorption, ICP, XRD, TEM, FT-IR, UV?Cvis and a temperature-programmed desorption (TPD) of pyridine. In fact, the catalyst Zr-MCM-41 (10) showed a greater performance in the acid-catalyzed acetylation of 1,2-dimethoxybenzene employing acetic anhydride as an acylating agent. Furthermore, the kinetics of the acetylation of 1,2-dimethoxybenzene over these catalysts have also been investigated.     

Action of acetic anhydride on benzo-1,5-diazepine derivatives

Under the action of acetic anhydride in benzene, 7-amino-2,4-dimethyl- and 2,4-dimethylbenzo-1, 5-diazepine undergo cleavage at the-C=N-bond with simultaneous acylation of the primary amino groups formed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 6, No. 8, pp. 1135–1137, August, 1970.     

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

The ESR spectra of -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.     

Solvolysis of 8-bromotheophylline by acetic anhydride in the presence of potassium fluoride

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, p. 699, May, 1991.