Reactions of N"-acyl- and N"-tosyl-substituted hydrazides of 2-aminobenzoic acid with carbonyl compounds

The reactions of N"-acyl and N"-tosyl-substituted hydrazides of 2-aminobenzoic acid with aliphatic, aromatic, and heterocyclic aldehydes or aliphatic ketones afforded 3-acyl- and 3-tosylamido-1,2-dihydroquinazolin-4-one derivatives, respectively. The structures of the reaction products were established by NMR spectroscopy and X-ray diffraction analysis.     

H4SiW12O40-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides: An efficient synthesis of 3,4-disubstituted 1H-pyrazoles

A simple and efficient method for the synthesis of pyrazoles through a silicotungstic acid(H₄Si W₁₂O₄₀)-catalyzed cyclization of epoxides/aldehydes and sulfonyl hydrazides has been developed. Various epoxides/aldehydes were smoothly reacted with sulfonyl hydrazides to furnish regioselectivity 3,4-disubstituted 1H-pyrazoles. The application of such an earth-abundant, readily accessible, and nontoxic catalyst provides a green approach for the construction of 3,4-di...     

Liquid-liquid extraction separation of zinc and cadmium with 1-phenyl-3-methyl-4-acyl-5-pyrazolones and tri-n-octylphosphine oxide

The extraction of zinc and cadmium with a mixture of a 1-phenyl-3-methyl-4-acyl-5-pyrazolone and trioctylphosphine oxide (TOPO) in various solvents is described. The extraction constants for systems based on eight 4-acyl compounds (C₃C₁₈) are reported. The 1-phenyl-3-methyl-4-stearoyl-5-pyrazolone/benzene system is most effective for the mutual separation of zinc and cadmium at pH 4.5; 20 μg of zinc can be separated efficiently from 20 mg of cadmium.     

Solvent extraction of calcium(II) and strontium(II) with 1-phenyl-3-methyl-4-acyl-5-pyrazolone

The extraction of calcium and strontium from aqueous solution with 1-phenyl-3-methyl-4-acyl-5-pyrazolone (C_n) in MIBK and benzyl alcohol has been studied. In the extraction of Sr with 4-acyl derivatives-MIBK systems, the pH_1/2 values change with increasing the length of acyl chain in the derivatives. The reagent C₃ is more suitable than the other reagents for the separation of Ca and Sr, using MIBK as solvent.     

Directive nature of the nitration of the oximes of 2-acetylthiophene and 2-propionylthiophene

A method of obtaining pure 2-acetyl- and 2-propionyl-5-nitrothiophenes by nitrating the oximes of the corresponding ketones with the subsequent isolation from the mixtures formed of the pure oximes of the 2-acyl-5-nitrothiophenes and their saponification has been developed. The pure 2-acetyl- and 2-propionyl-4-nitrothiophenes have been isolated by crystallization from the products of the nitration of the corresponding ketones, which form in each case a mixture of the corresponding 2-acyl-4-nitro- and 2-acyl-5-nitrothiophenes containing about 90% of the 4-nitro isomer.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1483–1486, November, 1973.     

Acetylenic ketones. Part VI. Reaction of aroylphenylacetylenes with hydrazine derivatives

The reaction of aroylphenylacetylenes (I) with acyl- or aroylhydrazines (II) gave ω-aroyl-acetophenone-N-acyl or N-aroylhydrazones (IV). The latter gave upon treatment with methanolic potassium hydroxide and with acetic anhydride in the presence of sodium acetate, the corresponding pyrazoles (V) and the N-acetylpyrazoles (VII and VIII), respectively. The acetylenic ketones ( 1 ) also reacted with methylhydrazine and 1,1-dimethylhydrazine to give 5-aryl-1-methyl-3-phenylpyrazoles (XII), and 1,1-dimethylhydrazine derivatives (XIII), respectively. When the latter compounds were heated with acetic anhydride, they gave the N-methylpyrazoles (XII).     

Synthesis of 1-arylacenaphtho[1,2-d]pyrazoles and 5,7-Dehydro-5H,7H-benzo[b]acenaphtho[1,2-e]-1,3a,6a-triazapentalenes

2-Benzoyl- 5 and 2-acetylacenaphthenone 6 , prepared from the corresponding 1-acyl-2-(1-pyrrolidinyl)-acenaphthylenes 2 and 3 , reacted with arylhydrazines 8 under acidic conditions to give the corresponding 1-arylacenaphtho[1,2-d]pyrazoles 9 and 10 . Novel heteropentalene mesomeric betaines, 5,7-dehydro-5H,7H-benzo[b]acenaphtho[1,2-e]-1,3a,6a-triazapentalenes 13 and 14 were prepared by reductive cyclization of 1-(o-nitrophenyl)acenaphtho[1,2-d]pyrazoles 9d and 10d , respectively.     

Cyclothiomethylation of carboxylic acid hydrazides with aldehydes and H<Subscript>2</Subscript>S

The cyclothiomethylation of carboxylic acid hydrazides RCONHNH₂ (R = C₅H₄N, Ph, 2-MeOC₆H₄, or 4-HOC₆H₄CH₂) with formaldehyde and H₂S at 70 °C affords predominantly the corresponding N-(1,3,5-dithiazinan-5-yl)amides, whereas this reaction at 0–−50 °C gives a mixture of the latter compounds with 3-acyl-1,3,4-thiadiazolidines. N-(1,3,5-Dithiazinan-5-yl)-amides were selectively synthesized by the reaction of carboxylic acid hydrazides with formaldehyde and H₂S in the presence of BuONa in BuOH.     

Distinguishing Features of reactions of 2-chloro-and 2,2-dichloro(bromo)vinyl ketones with alkyl-and arylhydrazines

2-Chlorovinyl alkyl ketones react with alkylhydrazines to give mixtures of 1-R-3-R′- and 1-R-5-R′-pyrazoles: The 1-R-3-R′-pyrazoles form through the heterocyclization of 2-chlorovinyl ketone alkylhydrazones whereas in the heterocyclization into 1-R-5-R′-pyrazoles N ¹-alkyl-N ²-(2-acylvinyl)hydrazines are involved. The regiospecific heterocyclization of 2-chloro-and 2,2-dichlorovinyl ketones with arylhydrazines and also of 2,2-dichloro(bromo)vinyl trifluoromethyl ketones with C alkylhydrazines into pyrazoles and 5-chloro(bromo)-pyrazoles proceeds through a stage of haloenones hydrazones formation. The study of the structure of the obtained 1-alkyl-3(5)-alkylpyrazoles by means of two-dimenaional ¹H and ¹³C NMR spectroscopy and GC-MS method made it possible to assign the proton and carbon signals of isomeric pyrazoles and to establish the diagnostic ions for the pair of 1,3-and 1,5-isomers.     

Boron trifluoride catalysed reactions of 2,2,2-trichloroethyl-6-diazopenicillanate with ketones: preparation of novel 6β-acyl-6α-alkyl(aryl) penicillanates.

The BF₃·Et₂O catalysed reactions of the diazopenicillanate 1 with ketones provide novel 6-acyl-6-alkyl(aryl)penicillanates 2, together with thiazolooxazinones 6 formed via penam C(5)-C(6) cleavage reactions.     

Chlorination of N-acyl Derivatives of p-Aminophenols (Naphthols) and p-Phenylenediamines

The chlorination of N-acyl derivatives of p-aminophenols can provide either N-acyl-2,3,6-trichloro-4-aminophenols or N-acyl-2,3,5,6-tetrachloro-1,4-benzoquinone imines depending on solvent nature, process temperature, and molar ratio initial compound-chlorine. The chlorination of N-acyl-4-amino-1-naphthols affords only N-acyl-2,3-dichloro-1,4-naphthoquinone imines. N,N'-Diacyl-1,4-phenylenediamines give rise on chlorination to a mixture of 2,5-dichloro-, 2,6-dichloro-, and 2,3-dichloro-N,N'-diacyl-1,4-phenylenediamines.     

Synthesis of 5-hydroxy- and 5-acylhydrazinopyrazolidines by the reaction of β-substituted hydrazides with α,β-unsaturated aldehydes and their biological activity

The reaction of -substituted hydrazides with alkenals (acrolein, methacrolein, crotonaldehyde, and cinnamaldehyde) serves as a method for the synthesis of the corresponding 1-acyl-5-hydroxypyrazolidines and, in a number of cases, 1-acyl-5-acylhydrazinopyrazolidines. Some of the 1-acyl-5-hydroxypyrazolidines obtained have antiphlogistic activity.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 659–666, May, 1984.     

1-Alkylpyrazoles and 1-alkyl-5-chloropyrazoles from halovinyl ketones and 1,1-dialkylhydrazines

Regioselective heterocyclization of alkyl 2-chloro-and 2,2-dichlorovinyl ketones with 1,1-dialkyl-hydrazines to 1,3-dialkyl-1H-pyrazoles and 1,3-dialkyl-5-chloro-1H-pyrazoles involves intermediate formation of the corresponding dialkylhydrazones. Fragmentation pattern of chlorine-containing pyrazoles, 3-chloromethyl-1-methyl-1H-pyrazole and 5-chloro-1-methyl-3-propyl-1H-pyrazole, depends on the position of the halogen atom.     

5(4)-Chloro-1-(2,4-dinitrophenyl)pyrazoles from 2,4-Dinitrophenylhydrazones of Chlorovinyl Ketones and β,β-Dichloroacrolein

A method has been developed for obtaining 3-alkyl(phenyl)-4(5)-chloro-1-(2,4-dinitrophenyl)pyrazoles from appropriate dinitrophenylhydrazones of 1-chloro-, 1,2-, and 2,2-dichlorovinyl ketones by heating the latter in polyphosphoric acid. The structure of the pyrazoles was studied by IR and ¹H NMR spectroscopy. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1012–1019, July, 2005.     

Application of SBA-Pr-SO<Subscript>3</Subscript>H as a nanoreactor in the one-pot synthesis of spiroquinazolinones

An efficient method for the synthesis of spiroquinazolinones was developed using isatoic anhydride, hydrazides and cyclic ketones, through a rapid one-pot three-component reaction in the presence of SBA-Pr-SO₃H under solvent-free conditions. SBA-Pr-SO₃H was an efficient heterogeneous nanoreactor with a pore size of 6 nm which can be easily handled and removed from the reaction mixture by simple filtration and can be reused several times without any loss of activity. The main advantages of using this nanoreactor are high product yields, being environmentally benign, short reaction times, and easy handling.     

Efficient one-pot synthesis of substituted pyrazoles

An efficient, one-pot synthesis of substituted pyrazoles from enones, hydrazides, and halides was developed. In comparison with the classical Knorr pyrazole synthesis, this methodology gave a different type of product (R³≥R⁵). A range of substituted pyrazoles were prepared in good to high yields with complete regioselectivity.     

Photochemische Reaktionen. 109. Mitteilung [1]. Zur Photochemie konjugierter δ-Keto-enone und β,γ,δ,ϵ-ungesättigter Ketone

Photochemistry of Conjugated δ-Keto-enones and β,γ,δ,?-Unsaturated Ketones On ¹π,π*-excitation the δ-keto-enones 5–8 are isomerized to compounds B ( 18 , 22 , 26 , 28 ) via 1,3-acyl shift and to compounds C ( 19 , 23 , 27 , 29 ) via 1,2-acyl shift, whereas the β,γ,δ,?-unsaturated ketone 9 gives the isomers 32 and 33 by 1,2-and 1,5-acyl shift, respectively. Furthermore, isomerization of 6 to 24 , dimerization of 8 to 30 and addition of methanol to 8 ( 8 → 31 ) is observed. Unlike 7 and 8 the acyclic ketones 5 , 6 and 9 undergo photodecarbonylation on ¹π,π*-excitation ( 5 → 20 , 21 ; 6 → 20 , 25 ; (E)- 9 → 35–38 ). Evidence is given, that the conversion to B as well as the photodecarbonylation of 5,6 and 9 arise from an excited singulet state, but the conversion to C as well as the dimerization of 8 from the T₁-state.     

Monoexcited singlet states and conformation of some acylpyridines

Substituent effects on the UV-spectra of formyl-, acetyl- and benzoylpyridines are investigated. The UV-bands are discussed by comparison with the calculated energies and oscillator strengths of all planar and twisted 2-acyl-, 3-acyl- and 4-acyl derivatives using the SCF CI-1 method. The structure of each ¹π^* ← ¹π transition is determined from the contributions of the individual MO transitions and their LCAO characteristics. The conformation of acylpyridines is discussed.     

Synthesis of 1-Acyl-5-amino-4-ethoxycarbonylpyrazoles from Monohydrazides of Cyclohexenedicarboxylic Acids and Ethyl Ethoxymethylenecyanoacetate

Heating monohydrazides of cyclohexenedicarboxylic acids with ethyl ethoxymethylenecyanoacetate at reflux gives the corresponding N-substituted hydrazides. This reaction carried out in pyridine gives 1-acyl-5-amino-4-ethoxycarbonylpyrazoles. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1332–1335, September, 2005.     

The synthesis of 6,7-dihydro-5H-pyrrolo[3,4-d]pyrimidines. II. 4-Hydroxy, 4-mercapto, 2-amino-4-hydroxy and 2,4-dihydroxy derivatives

Several new types of compounds in the 6,7-dihydro-5H-pyrrolo[3,4-d]pyrimidine series have been prepared. Included are a 6-acyl derivative unsubstituted in the pyrimidine ring, as well as 4-hydroxy, 4-mercapto, 2-amino-4-hydroxy and 2,4-dihydroxy derivatives. These products were derived directly or indirectly from 4-cyano- or 4-carbethoxy-1-acyl-3-amino-3-pyrroline intermediates. 3-Hydroxy, 3-amino, and 3-thioformylamino-1-acyl-3-pyrroline-4-thiocarboxamides have been obtained and the 3-thioformylamino derivatives shown to undergo base-catalyzed cyclization to close a 4-mercaptopyrimidine ring.