Heterocyclic Ketones Research Articles

Synthesis of chalcone analogs and derivatives of 2-pyrazoline from 3-formylindole

By the crotonic condensation in an alkaline medium of 3-formylindole with various aromatic and heterocyclic methyl ketones, and also with cyclopentanone, cyclohexanone, and 1,4-diacetylbenzene, we have synthesized nineteen α,β-unsaturated ketones. The majority of them were characterized as the 2,4-dinitrophenylhydrazones, the absorption maxima of which in chloroform are given. Some considerations are expressed concerning the reactivity of 3-formyl- and 3-acetylindoles. Ten 3-aryl-1-phenyl-5-(indol-3-yl)-2-pyrazolines and their analogs with a 3-heterocyclic residue have been synthesized by the reaction of 3-aryl-1-(indol-3-yl)propen-3-ones and the corresponding analogs with phenylhydrazine. Some of the compounds synthesized possess a bright luminescence.

Synthesis of 2-methyl-3-carbethoxypyrylium salts by the condensation of ethoxymethyleneacetoacetic ester with ketones

A method is proposed for the synthesis of 2-methyl-3-carbethoxypyrylium salts by the acid condensation of ethoxymethyleneacetoacetic ester with alkyl aryl, heterocyclic, and cyclic ketones or resorcinol. 2-Methyl-3-carbethoxy-6-phenylpyrylium perchlorate was condensed with benzaldehyde, and the product was subjected to acid hydrolysis and decarboxylation to 2-methyl-6-phenylpyrylium perchlorate to confirm the structure of the synthesized salts.

Synthesis of 2,4-substituted 5,6-benzoquinolines

By the catalytic condensation of azomethines with aliphatic-aromatic and heterocyclic ketones, derivatives of 5,6-benzoquinoline containing thiophene or pyridine rings as substituents have been synthesized.

Organosilicon compounds : XII. Anhydride, acid halide and chloroformate cleavage of the siliconcarbon bond of 2-silylsubstituted pyridines

Cleavage of the siliconcarbon bond of 2-(trimethylsilyl)pyridine has been affected by benzoyl chloride, phthalic anhydride, and ethyl chloroformate as well as benzaldehyde to provide a novel pathway to heterocyclic ketones, keto-acids, esters and alcohols. A cyclic four-membered transition state is proposed in which the polarity of both the siliconaromatic bond and the attacking reagent are stressed.

Basicity and structure of ?,?-unsaturated heterocyclic ketones

Basicity and structure of ?,?-unsaturated heterocyclic ketones

A study of some condensation products in the 2-phenylthiophene series

A number of previously unreported α, β-unstaurated ketoncs of the 2-phenylthiophene series has been synthesized by the crotonic condensation of 2-acctyl-5-phenylthiophene with aromatic and heterocyclic aldehydes and of 2-formyl-5-phenylthiophene with aliphatic-aromatic and heterocyclic ketones in an alkaline medium.

Synthesis of ?, ?-unsaturated diketones and derivatives of 2-pyrazoline from 2, 5-diformylthiophene

The crotonic condensation of 2, 5-diformylthiophene with various aromatic and heterocyclic methyl ketones has given 15 α, β-unsaturated diketones. By the reaction of the latter with phenylhydrazine, ten 2, 5-di(1′-phenyl-3′-R-Δ2-pyrazolin-5′-yl)thiophenes possessing a bright blue-violet or green luminescence have been synthesized.

Basicity and structure of ?,?-unsaturated heterocyclic ketones

Basicity and structure of ?,?-unsaturated heterocyclic ketones

Syntheses of 1-spiro-isoquinoline derivatives by phenolic cyclization (studies on the syntheses of heterocyclic compounds. CCCXXXV.)

Syntheses of 1-spiroalkano-, 1-spiroheteroalkano-, and 1, 1-disubstituted 1, 2, 3, 4-tetrahydroisoquinolines are described. 3-(2-Aminoethyl)phenol as a starting material was synthesized as follows. Demethylation of m-methoxyphenylacetonitrile, which was obtained by benzyne reaction of o-chloroanisole with acetonitrile, with pyridine hydrochloride gave m-hydroxyphenylacetonitrile, whose ethanolic solution saturated with ammonia was hydrogenated in the presence of Raney nickel and gave the expected 3-(2-aminoethyl)phenol. On the other hand, one cycloalkanone, cyclohexanone, three heterocyclic ketones, 1-methyl-4-piperidone, 1-benzyl-4-piperidone, and 2, 3, 5, 6-tetrahydro-1, 4-thiapyrone, and four noncyclic ketones, acetone, ethyl methyl ketone, benzaldehyde, and acetophenone, were used as one of the starting materials, followed by usual phenolic cyclization, to afford eight kinds of the corresponding new tetrahydroisoquinolines.

Research on some condensation products in the 2, 2?-dithienyl series II

Crotonoid condensation of 5-formyl-2,2′-dithienyl with some aromatic and heterocyclic ketones in alkaline medium is used to synthesize a number of hitherto undescribed α,β unsaturated ketones of the 2,2′-dithienyl series. All the compounds investigated give intensely colored halochromic solutions in sulfuric acid.

Synthesis of chalcone analogs containing a pyrrole ring

Crotonaldehyde-type condensation in alkaline medium of 2-acetylpyrrole or pyrrole-2-aldehyde with aromatic or heterocyclic aldehydes and methyl ketones gives a number of hitherto undescribed pyrrole analogs of chalcone, and their 2, 4-dinitrophenylhydrazones are prepared.

Basicity and structure of ?, ? -unsaturated heterocyclic ketones

The protolytic equilibrium constants of chalcone and its furan and thiophene analogs have been measured spectrophotometrically in sulfuric acid — glacial acetic acid solution. It is shown that the furan ketones are more basic than the thiophene ones, basicity depending on the position of the carbonyl group in the conjugated chain. In the systems studied, 2-furyl exhibits an appreciably greater positive dynamical conjugation effect than 2-thienyl, but as compared with the latter it gives rise to less steric hindrance to solvation of carbonium ions.

Notes- Novel Synthesis of Heterocyclic Ketones

Notes- Novel Synthesis of Heterocyclic Ketones

200. Heterocyclic ketones. Part II. β-Amino-ketones containing thiophen, thiazole, and furan nuclei, and their behaviour towards phenylhydrazine

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