A study of the synthesis and some reactions of perimidines

A study of the preparation of perimidines from 1,8-diaminonaphthalene and carbonyl compounds is presented. The optimum conditions for the reaction of the above diamine with carboxylic acids and esters, acid chlorides, anhydrides and aldehydes are defined. The chemical behavior and a number of previously unreported reactions of perimidines are presented. The latter include N-alkylations, reductions, oxidations and acylations.     

Synthesis of polyfluorinated ketonesvia the ate-complexes

Russian Chemical Bulletin - Asymmetric polyfluorinated ketones RFCOR are formed by treating various derivatives of (polyfluoro)alkanoic acids (esters, anhydrides, acid chlorides) with lithium...     

Umsetzung sekundärer Phosphine mit aromatischen Sulfonsäuren, 3. Mitt.: Umsetzung mit Sulfochloriden

Reaction of sec. phosphines with sulfonyl chlorides in the presence of pyridine gives thiophosphinates. Some of these esters were prepared and a possible reaction mechanism is discussed. Reaction of Ag-diphenylphosphinate with sulfonyl chlorides gave mixed anhydrides of phosphinic and sulfonic acids.     

O-acyl derivatives of cyclopentanone and cycloheptanone oximes

By acylation of cyclopentanone and cycloheptanone oximes with carboxylic acids anhydrides or chlorides new esters were obtained of cyclopentanone and cycloheptanone oximes and their spectral characteristics were investigated.     

Synthesis of α,β-epoxy diazomethyl ketones

The preparation of eighteen epoxy diazomethyl ketones 1 is described. Two general methods were developed. Firstly, treatment of the mixed anhydrides of glycidic acids and carbonic acid ester with diazomethane led to the title compounds in yields ranging from 17–74%. Secondly, glycidyl chlorides which were obtained from sodium glycidates and oxalyl chloride, gave the desired products upon treatment with diazomethane (yields 60–74%). The required α,β-epoxy carboxylic esters were prepared by Darzens condensation and epoxidation of α,β-unsaturated esters, but in some cases also by reaction of α-oxo carboxylic esters with diazomethane.     

Calcium alkoxyalanates : III. Reduction of organic functional groups by calcium tetrakis(alkoxy)alanates

Calcium tetrakis(alkoxy)alanates obtained from different alcohols reduce aldehydes, ketones, acids, esters, acid chlorides and anhydrides to alcohols in high yields. Good results are achieved in the reduction of amides to amines. The reductions of nitrile and oxime groups and dehalogenation reactions are more difficult. Selectivity is possible in the reduction of organic epoxides.     

Newer acylation methods for the determination of organic hydroxyl and amino compounds

A critical review of certain acylation methods for the determination of organic hydroxyl and amino compounds is presented. Esterification methods developed after 1955, involving seven anhydrides and five acid chlorides, are discussed. A brief survey is given of acid-catalysed acetylation and of colorimetric methods based on the esterification reactions.     

2-chloro-4,6-disubstituted-1,3,5-triazines a novel group of condensing reagents

The title, compounds form in reaction with carboxylic acids highly reactive intermediates, which are useful as acylating reagents in the preparation of esters, amides, acid anhydrides, and peptides in 64–98% yield.     

Comparison of ascorbic acid and related compounds as interference suppressors in electrothermal atomic absorption spectrometry

Suppression of interferences from sodium, calcium and iron(III) chlorides by addition of ascorbic acid and related compounds was investigated for the determination of Pb, Sn, Mn, V and Mo. Absorption—time curves for these metals with and without ascorbic acid and other compounds showed that the peak appeared earlier for Pb, and later for Sn, Mn, Mo and V when ascorbic acid was present. Suppression of interferences was also achieved, but usually less effectively, by lactones, carboxylic acids, ammonium carbonate and formaldehyde. Carbon monoxide or dioxide generated by pyrolysis of the suppressors may participate in the suppression of interferences.     

Nickel-Catalysed Reactions of Allyl Halides and Related Compounds

Allyl compounds react with carbon monoxide, or with carbon monoxide and acetylene, in the presence of tetracarbonylnickel as catalyst. These catalysts are involved also in coupling reactions and addition reactions of activated olefins and ketones. Reactions of this type can be used for the preparation of unsaturated aliphatic acids, esters, nitriles, hydrocarbons, alicyclic ketones, keto acids, keto esters, diketones, lactones, phenols, and other compounds. The reactions proceed via π-allylnickel complexes.     

Reaction of Hexamethyldisilazane with Cyclic Anhydrides of Organic Acids: A New Route to N-Trimethylsilylimides of Di- and Tetracarboxylic Acids

Cyclic anhydrides of di- and tetracarboxylic acids react with hexamethyldisilazane to give the corresponding N-trimethylsilylimides in 90-96% yields. However, cyclic anhydrides of succinic, 4-nitrophthalic, and tetrachlorophthalic acids react differently, giving acyclic trimethylsilyl esters of mono-N-trimethylsilylamides of these acids in 90-93% yields. The ¹H NMR, IR, and mass spectra of the compounds synthesized were studied.     

Synthesis of New Heterocyclic Mono‐ and Bisorganophosphorus Acids and Their Derivatives with 1,2‐Phenylene Fragments

The interaction of esters of phosphorous acid containing POSiMe₃ and PH fragments with anhydrides of phthalic and 2‐sulfobenzoic acids is proposed as convenient methods for the synthesis of new heterocyclic mono‐ and bisorganophosphorus acids and their derivatives with 1,2‐phenylene fragments, carboxyl and sulfonyl groups. Also some properties of the obtained compounds are presented.     

Gas chromatographic determination of carboxylic acid chlorides and residual carboxylic acid precursors used in the production of some penicillins.

An improved gas chromatographic method is described for the simultaneous determination of carboxylic acid chlorides and related carboxylic acids used in the production of some commercial semisynthetic penicillins. The acid chloride reacts with diethylamine to form the corresponding diethylamide. Carboxylic acid impurities are converted to trimethylsilyl esters. The two derivatives are separated and quantitated in the same chromatographic run. This method, an extension of the earlier procedure of Hishta and Bomstein (1), has been applied to the acid chlorides used to make oxacillin, cloxacillin, dicloxacillin, and methicillin (Figure 1); it shows promise of application to other acid chlorides. The determination is more selective than the usual titration methods, which do not differentiate among acids with similar pK's. Relative standard deviations of the acid chloride determination are 1.0-2.5%. Residual carboxylic acid can be repetitively determined within a range of 0.6% absolute.     

Tetrahydrofuran Ring Opening with Acyl Chlorides or Anhydrides Catalyzed by Gallium Triiodides: A Novel and Facile Method for the Preparation of Iodo Esters

Recently gallium and its compounds are gradually attracting attention as useful reagentsin organic synthesis'-'. Gallium enolate-mediated intermolecular aldol reaction andaddition reaction of Q -bromoketone with imine, a straightforward and versatilepreparation of propargylic alcohols from l-alkynes and aldehydes via Gal, and aminehave been documented3. Kobayashi reported that gallium reagents could efficientlypromote the glycosidation of glycopyranosyl fluorides'. The reaction of alkyne with…     

Homogeneous catalytic hydrogenation of free carboxylic acids in the presence of cluster ruthenium carbonyl hydrides

Saturated monocarboxylic acids up to C₆, several bicarboxylic acids and some of the corresponding anhydrides are hydrogenated in the homogeneous phase with H₄Ru₄(CO)₈(PBu₃)₄ as catalyst to give the corresponding alcohols (present among the reaction products as esters) or lactones at 100–200°C under a pressure of 100–200 atm of hydrogen. Anhydrides react at temperatures lower than those needed for acids. Esters are not reduced. Only δ-valerolactone is hydrogenated to 1,5-pentanediol. Ruthenium carbonyl carboxylates have been recovered at the end of the reaction and appear to be catalytically active intermediates.     

Organic syntheses on an icosahedral borane surface: closomer structures with twelvefold functionality

The syntheses of a series of novel ester-linked derivatives of the icosahedral [closo-B12(OH)12]2- boron cluster (closomer esters) are described using several synthetic methods. The reaction of bis(tetrabutylammonium)-closo-dodecahydroxy-dodecaborate, [NBu4]2 1, with carboxylic acid chlorides and anhydrides, vinyl esters with a Y5(OiPr)13O catalyst and 1,1'-carbonyldiimidazole-activated carboxylic acids yields the corresponding dianionic dodeca-ester closomers. The method using 1,1'-carbonyldiimidazole-activated carboxylic acids may be employed as a general synthetic strategy. The use of elevated reaction temperatures, achievable under pressure, to expedite syntheses is described. An attractive methodology using immobilized scavenger reagents for the expeditious purification of the closomer esters was employed. The developed methodology is compatible with a variety of peripheral functional groups attached to the termini of densely packed, carboxylate ester-linked radial arms bonded to the icosahedral borane surface. A closomer ester having twelve terminal amino groups was prepared, and without isolation, fully acetylated in good yield.     

Preparative synthesis of cyclohexanone oxime esters

Preparative procedures have been developed for the synthesis of cyclohexanone oxime esters by acylation of cyclohexanone oxime with carboxylic acid anhydrides in the presence of perchloric acid or with carboxylic acid chlorides in the presence of pyridine.     

Synthetic Approaches to Selenoesters

Selenoesters are compounds of great synthetic relevance since they can be used in several types of chemical transformations and mainly due to their great capacity in the formation of acyl radicals. Therefore, the scientific community has been developing several methods for the synthesis of this class of molecules. This review will address the synthesis of these compounds from different starting materials, such as carboxylic acids derivatives (acid chlorides and anhydrides), aldehydes, selenoacetylenes and miscellaneous methods.     

Preparation of enol ethers by carbonyl olefination utilizing an alkoxymethyl chloride-titanocene(II) system

Aldehydes, ketones, esters and lactones are transformed into enol ethers or 1,2-dialkoxy-1-alkenes by treatment with organotitanium species prepared from alkoxymethyl chlorides and a titanocene(II) complex.     

Reaction of mixed carboxylic anhydrides with grignard reagents : Application to the preparation of keto esters; scope and limitations

The low-temperature Grignard reaction of mixed carboxylic anhydrides derived from acid chlorides and o-anisic acid to the general synthesis of keto esters is demonstrated for compounds 1–6, although, some limitations on substrate and Grignard reagent species are also encountered; attempts in the oxa series 2 are unsuccessful, and reaction with ω-phenylpropyl Grignard species for 1 and 4 shows a drastic decrease in yields of the keto esters for m-methoxy analogues. Anomalous behaviour may be associated with an alternative type of specific metal-coordination complex which includes the ether oxygen atom properly situated in the substrate or the reagent