Benzoylacetic Esters Research Articles

3‐Aryl‐2‐chloropropanals in Hantzsch Synthesis of Pyrroles.

AbstractFor Abstract see ChemInform Abstract in Full Text.

3-Aryl-2-chloropropanals in Hantzsch Synthesis of Pyrroles

Pyrroles have been obtained by the Hantzsch method, by reaction of α-halocarbonyl and 1,3-dicarbonyl compounds in the presence of ammonia [1-3]. However, the range of α-halo-substituted aldehydes used in this synthesis is quite limited [1-4]. In this paper, we show that in this reaction we can use 3-aryl-2-chloropropanals 1a-d, obtained by Meerwein chloroarylation of acrolein [5]. We have established that aldehydes 1a-d react under mild conditions with acetoacetic and benzoylacetic esters in the presence of ammonia to form ethyl esters of 4(R-benzyl)-2-methyl(phenyl)pyrrole-3-carboxylic acids 2a-e. Dehydrochlorination of α-chloro aldehydes 1a-d does not occur in this case. Pyrrole is formed as a result of C-alkylation of the intermediate enamine followed by cyclization. The proposed method allows us to obtain trisubstituted pyrroles containing benzyl substituents in the 4 position.

Synthesis of 4,6-bis(1H-1,2,3-triazolyl)pyrimidines by the reaction of 4,6-diazido-2-(4-methoxyphenyl)-pyrimidine with compounds containing a reactive methylene group

The reaction of 4,6-diazido-2-(4-methoxyphenyl)pyrimidine with cyanoacetic ester in the presence of triethylamine leads only to 4-azido-6-amino-1-(4-methoxyphenyl)pyrimidine. The main product in reactions with 1,3-dicarbonyl compounds (acetylacetone, acetoacetic and benzoylacetic esters) is the corresponding substituted 4,6-bis(1H-1,2,3-triazolyl)pyrimidine. The formation of 4-azido-6-(1H-1,2,3-triazolyl)pyrimidine and 4-amino-6-(1H-1,2,3-triazolyl)pyrimidine as minor products was also recorded.

Electrochemical oxidative dimerization of acetoacetic and benzoylacetic esters in the presence of metal halides

Acetoacetic and benzoylacetic esters dimerize on electrolysis in the presence of metal halide mediators to form 2,5-dioxohexane-3,4-dicarboxylic and 1,4-dioxo-1, 4-diphenylbutane-2,3-dicarboxylic esters in yields up to 90%. Primarily the meso-form of the dimer is produced (up to 90%) under optimal conditions (NaI, −20°C) in acetone and acetonitrile. Diastereomers of the dimer are produced in comparable amounts in methanol and ethanol.

ChemInform Abstract: Polycyclic Aromatic Alkaloids. Part 2. Synthesis of Onychine and Eupolauridine.

AbstractThe benzoylacetic ester (II) reacts with crotonaldehyde (I) in the presence of hydroxylamine hydrochloride (III) to give the phenylpyridinecarboxylate (IV).

Synthesis and pharmacological activity of 2-aryl-3-ethoxy-carbonyl-5-hydroxybenzofurans

considerable number of 2-aryl-5-hydroxybenzofurans display antifungal [13], antibacterial [ii], ~-adrenoblocking [I0], anticonvulsant and psychotropic activity [2, 7]. For this reason, it was of interest to synthesize analogs of fenicarberan containing various substituents in the phenyl substituent, namely one or more methoxy groups, chlorine, bromine, or iodine atoms. Reaction of anisic acid [13], veratric acid, 3,5-dibromo- [14], 3,5-diiodo- [20], 3,5dichloro-4-methoxybenzoic acid [17], or 3,4,5-trimethoxybenzoic acid [15] with an excess of thionyl chloride gave the acid chlorides, which were treated without further purification with acetoacetic easter. There were obtained the known 4-methoxy [19] and 3,4,5-trimethoxybenzoylacetic ester [16], together with the novel 3,4-dimethoxy- (I), 3,5-dibromo-4-methoxy(II), 3,5-dichloro-4-methoxy- (III), and 3,5-diiodo-4-methoxybenzoylacetic esters (IV). Condensation of the substituted benzoylacetic esters with p-benzoquinone as described in [3] afforded 3-ethoxycarbonyl-5-hydroxybenzofurans, bearing in the 2-position the substituents4'~methoxy - (V), 3',4'-dimethoxy- (Vl), 3',4',5'-trimeth oxy- (VII), 3',5'-dibromo-4'methoxy- (VIII), 3',5'-dichloro-4'-methoxy- (IX), and 3',5'-diiodo-4'methoxyphenyl (X). As by-products in the condensation of (I-IV) with p-benzoquinone, there were isolated 2-16% of the diethyl 2,6-diarylbenzo[l,2-b:4,5-b]difuran-3,7-dicarboxylates (XI-XIV). Heating (V-X) in DM_F with formamide and Me2NH-HCI gave the 4-dimethylaminomethy ! derivatives. In the case of (VII), it was shown that the Mannich reaction when carried out with an equimolar amount of bisdimethylaminomethane in dioxane also gave the monoaminomethyl derivative (XVI). The use of an excess of bisdimethylaminomethane and increasing the reaction time resulted in the formation of the 4,6-bisdimethylaminomethyl derivatives (XXI-XXII). An exception was 2-(4'-methoxyphenyl)-3-ethoxycarbonyl-4-dimethylaminomethyl-5-hydroxybenzofuran (XX). Under the conditions for the synthesis of the disubstituted product (XXIII), we obtained high yields of the monosubstituted compound (XX) only. 2-(4-Methoxyphenyl)-3ethoxycarbonyl-4,6-bis(dimethylaminomethyl)-5-hydroxybenzofuran (XXIII) was only obtained when the aminomethylation of ()IX) with bisdimethylaminomethane was carried out in acetic acid.

Bromo derivatives of 4-phenyl-2,3-dihydro-1h-1,5-benzodiazepin-2-one

Monobromo and dibromo derivatives were synthesized by bromination of 4-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-2-one with bromine under various conditions and with N-bromosuccinimide in CCl4. 7-Bromo- and 8-bromo-4-phenyl-2,3-dihydro-1H-1,5-benzodiazepin-2-ones were obtained by condensation of 4-bromo-o-phenylenediamine with benzoylacetic ester in refluxing xylene. The UV and PMR spectra of the products are discussed.

Specificity in the formation of a seven-membered ring in the synthesis of dihydro-1.5-benzodiazepinones from aromatic diamines

It is shown that a mixture of 7- and 8-substituted 2,3-dihydro-1,5-benzodiazepinones is formed in the reaction of unsymmetrical aromatic diamines (4-chloro-,4-methyl-, and 4-methoxy-o-phenylenediamines) with acetoacetic and benzoylacetic esters under severe conditions. The corresponding anilide of benzoylacetic acid, the cyclization of which again leads to a mixture of isomeric dehydrobenzodiazepinones, can be isolated (in the case of benzoylacetic ester) when the concentrations of the reacting substances and the reaction time are decreased; this makes it possible to assume amidation of the Β-keto acids as one of the steps in the high-temperature synthesis of dihydrobenzodiazepinones. The quantitative ratio of the isomers formed in the reaction was determined by UV spectroscopy. The UV, IR, and PMR spectral data are presented.

Mononuclear heterocyclic rearrangements—vi : Conversion of 1,2,4-oxadiazoles into imidazoles

The rearrangement of N - (1,2,4 - oxadiazol - 3 - yl)β - enamino ketones 3 a–d and N-(1,2,4 - oxadiazol - 3 - yl)β - enaminoesters 3 e–h into 2 - acylamino - imidazolyl derivatives 9 a–h by the action of sodium ethoxide in N,N-dimethylformamide is the first example of a mononuclear heterocyclic rearrangement involving a nucleophilic carbon. Compounds prepared by condensation of 3 - amino - 1,2,4 - oxadiazoles 1 a–b with β - dicarbonyl compounds 2 a–d, show spectroscopic properties in agreement with cis-chelated structures 4. By condensation between 1 a–b and benzoylacetic ester 2 d, N - (1,2,4 - oxadiazol - 3 - yl)β - ketoamides 6 a–b have been obtained as secondary products. In solution, these compounds are in equilibrium with the corresponding tautomers 7 a–b.

Reactions of 2,3-dimethylindole and tetrahydrocarbazole with N-bromosuccimide

Reaction of 2,3-dimethylindole and tetrahydrocarbazole with N-bromosuccimide in the presence of pyridine gave the corresponding pyridinium bromides (I and XI) which were condensed acetoacetic ester, benzoylacetic ester and malonic ester in the presence of potassium carbonate.

Dinitrobenzene誘導体と活性メチレン化合体との反応に関する研究 (第4報)

Condensation of acetoacetic ester and benzoylacetic ester with methyl 2- or 4-chloro-3, 5-dinitrobenzenesulfonate is impossible, while that with phenyl 2- or 4-chloro-3, 5-dinitrobenzenesulfonate gave condensation products. Ketonic decomposition of these compounds afforded phenyl dinitrobenzenesulfonate of acetonyl or phenacyl, but their saponification to the objective free sulfonic acid was not effected. Considering these results and the sulfonic esters capable of undergoing ketonic decomposition and saponification at the same time, the ester of 2-ethoxyethanol was used and a good result was obtained. 2-Ethoxyethanol ester of 2- or 4-chloro-3, 5-dinitrobenzene-sulfonic acid was prepared and its condensation with acetoacetic ester and benzoyl-acetic ester was carried out. The products thereby obtained underwent smooth ketonic condensation and saponification at the same time, and the free acids and their potassium salts, i.e. 2- or 4-acetonyl- and 2- or 4-phenacyl-3, 5-dinitrobenzenesulfonic acids were obtained. S-Benzylthiuronium salts of these compounds were prepared. The S-benzylthiuronium salts reported in Part III of this series*1 were found to be identical with the salts of 2-acetonyl or 2-phenacyl compounds. These facts show that 3, 5-dinitrobenzenesulfonic acid undergoes condensation with acetone and acetophenone, in the presence of alkali, condensation taking place at position 2 to the sulfonic acid, and (XXV) is formed.

SYNTHESES AND ABSORPTION SPECTRA OF 1-CHLOROPHENYL-3-PHENYL-4-ALKYL-5-PYRAZOLONES AND PYRAZOLONES-4-C14

Monosubstituted benzoylacetic esters C6H5COCH(R)CO2C2H5 (R = H, CnH2n+1 (n = 1 to 9), and C6H5CH2) obtained by the condensation of n-alkyl halides with ethyl benzoylacetate were reacted with o-, m-, and p-chlorophenyl hydrazines to give 1-chlorophenyl-3-phenyl-4-alkyl-5-pyrazolones. Pyrazolones-4-C14 were prepared by the action of the same hydrazines on ethyl benzoylacetate-α-C14 obtained from benzoyl chloride and ethyl malonate-2-C14. Their activities were 801, 894, and 847 c./min. respectively. The ultraviolet and infrared absorption spectra of all the pyrazolones were determined and the most probable structures ascribed to the compounds.

SYNTHESIS, POTENTIOMETRIC TITRATIONS, AND SPECTRA OF PYRAZOLONES

Monosubstituted benzoylacetic esters, obtained by condensation of n-alkyl halides with ethyl benzoylacetate, were reacted with hydrazine and phenylhydrazine to give 3-phenyl and 1,3-diphenyl 5-pyrazolones monosubstituted in position 4 by alkyl radicals R (R = H, CnH2n+1(n-1 to 10), and C6H5CH2.). The dissociation constants of the pyrazolones were determined by potentiometric titrations. A study was made of the ultraviolet absorption spectra in both neutral and acid medium and of the infrared absorption spectra. X-ray powder diffraction patterns and data of the pyrazolones were obtained.

CXXVI.—The labile nature of the halogen atom in organic compounds. Part VIII. The action of hydrazine on the halogen derivatives of acetoacetic and benzoylacetic esters and of benzoylacetone

CXXVI.—The labile nature of the halogen atom in organic compounds. Part VIII. The action of hydrazine on the halogen derivatives of acetoacetic and benzoylacetic esters and of benzoylacetone