Synthesis and hydrolytic cleavage of 1-aryl-5-cyano-6-(2-dimethylaminovinyl)-4-oxo(thioxo)-1,4-dihydropyrimidines

1-Aryl-5-cyano-6-(2-dimethylaminovinyl)-4-oxo-1,4-dihydropyrimidines and their 4-thioxo analogs, which were prepared in three steps from cyanoacetamide and cyanothioacetamide, respectively, were subjected to hydrolysis. In aqueous AcOH, hydrolysis of N-(dimethylaminomethylene)-2-cyano-5-dimethylamino-2,4-pentadieneamide derivatives containing amino groups at position 3 afforded formylpyridones. The reaction of 2-cyano-3-dimethylaminothiocrotonamide with DMF dimethyl acetal gave rise to 3-cyano-4-dimethylamino-2-methylthiopyridine.     

Action des Enamines Sur Les Allenes Phosphores: Synthese de 1-( N -morpholino ou N -pyrrolidino)-phosphomethylenbicycloalcanes

In this work we studied the reaction of enamines 1 with allenylphosphonates and -phosphine oxides 2 which lead to the 1-( N -morpholino or N -pyrrolidino)-phosphomethylen-bicyclolkanes 3 . The structure of compounds 3 was confirmed by NMR-( 1 H, 13 C, and 31 P) and IR spectroscopy.     

Synthesis and x-ray crystal structure oftrans-diaquabis (4-morpholino) acetatocopper (II)

Summary An efficient procedure for the synthesis of the potassium salts of (4-morpholino)acetic acid, HL, and its -substituted derivatives is described. The title complex has been prepared and characterized by x-ray crystallography:a=8.505(2),b= 7.901(1),c=12.253(2) Å, =110.48(1)°, space groupP2₁/c,Z = 2, R_F=0.038 for 2300 observed MoK data. Hydrogen bonds link the centrosymmetrictrans-octahedral bis-chelated CuL₂(H₂O)₂ moieties into layers parallel to (100) in the crystal lattice.     

Diels-alder reaction of (E)-4-(2-nitroethenyl)-1H-imidazoles and methyl (E)-3-(1-imidazol-4-yl)propenoates

Diels-Alder reaction of methyl (E)-3-(1H-imidazol-4-yl)propenoates 2, 3a-c and (E)4-(2-nitroethenyl)-1H-imidazoles 3d,e with 2,3-dimethyl-1,3-butadiene, cyclopentadiene, and cyclohexa-1,3-diene gave the corresponding cycloadducts 6–9 .     

Synthesis and structure of 3-arylamino-2-(quinolin-2-yl)tropones

A reaction of substituted 2-(quinolin-2-yl)-1,3-tropolones with POCl₃ leads to the new3-chloro-2-(quinolin-2-yl)tropone derivatives. New 2-(4-arylaminoquinolin-2-yl)-3-aryl-aminocyclohepta-2,4,6-trien-1-ones and 2-[4-morpholino(piperidino)quinolin-2-yl]-3-aryl-aminocyclohepta-2,4,6-trien-1-ones were obtained by nucleophilic substitution reaction of the halogen atom in 2-(4-chloroquinolin-2-yl)-3-chlorotropones and 3-chloro-2-[4-morpholino-(piperidino)quinolin-2-yl]tropones. Molecular structures of 3-chloro-2-(quinolin-2-yl)tropone and 3-arylamino-2-(quinolin-2-yl)tropone were established by X-ray diffraction analysis. Energy and structural characteristics of isomers of 3-arylamino-2-(quinolin-2-yl)tropones in the gas phase and in solution were calculated by the density functional theory method (PBE0/6-31G**).     

1-Bis(methoxy)-4-bis(methylthio)-3-buten-2-one: useful three carbon synthon for synthesis of five and six membered heterocycles with masked (or unmasked) aldehyde functionality

1-Bis(methoxy)-4-bis(methylthio)-3-buten-2-one has been shown to be a useful three carbon synthon for efficient regiospecific synthesis of a variety of five (pyrazole and isoxazole) and six membered (pyrimidines, pyridone and pyridines) heterocycles with masked (or unmasked) aldehyde functionality by cyclocondensation with bifunctional heteronucleophiles such as hydrazine, hydroxylamine, guanidine, thiourea, cyanoacetamide and substituted β-lithioaminoacrylonitriles. Reaction of 1-bis(methoxy)-4-bis(methylthio)-3-buten-2-one with methylene iodide and Zn-Cu couple under Simmons-Smith reaction conditions afforded 2-(methylthio)thiophene-4-aldehyde in good yield, whereas cycloaromatization with thiophene-2- and 3-acetonitriles gave the corresponding substituted benzothiophene-4- and 7-aldehydes in good yields.     

Reactions of 5-aryl-4-acyl-1-(4-hydroxyphenyl)-3-hydroxy-3-pyrrolin-2-ones with arylamines

The reaction of 5-(4-chlorophenyl)-4-benzoyl-1-(4-hydroxyphenyl)-3-hydroxy-3-pyrrolin-2-one with aromatic amines affords the corresponding 3-arylamino derivatives, and the reactions of 5-aryl-4-acetyl-1-(4-hydroxyphenyl)-3-hydroxy-3-pyrrolin-2-ones with p-toluidine yield 5-aryl-4-(1-p-tolylamino)ethylene-1-(4-hydroxyphenyl)pyrrolidin-2,3-diones.     

Ring closure of 1-[4-(imidazol-1-yl)phenyl]-3-phenyl-2-propen-1-one derivatives to potential biologically active compounds

1-[4-(Imidazol-1-yl)phenyl]-3-phenyl-2-propen-1-one 1 reacted with acetone cyanohydrin, ethyl phenylacetate and cyanoacetamide to give the adducts 2, 8 and 10 respectively. Action of hydrazine hydrate on both the γ-ketonitrile 2 and the corresponding γ-ketoacid 4 led to pyridazine derivatives 3 and 5 . 4,5-Dihydropyridazinone 5 was dehydrogenated by the action of bromine in acetic acid to give pyridazinone 6 . Cyclization of acid 8 in acetic medium resulted in α-pyrone 9 . Cyanopentanamide 10 was converted with hydrochloric acid into δ-ketoacid 13 which led to α-pyrone 14 via an intramolecular dehydration. Refluxing 10 in the presence of acetic acid and ammonium acetate gave 3,4-dihydropyridone 11 which was dehydrogenated to produce pyridone 12 .     

Unexpected synthesis and crystal structure of ethyl 3-benzoyl-2,6-bis(2-chlorophenyl)-1-cyano-4-hydroxy-4-phenylcyclohexane-1-carboxylate

Three-component condensation of dibenzoylmethane with o-chlorobenzaldehyde and cyanoacetamide in the presence of piperidine gave ethyl 3-benzoyl-2,6-bis(2-chlorophenyl)-1-cyano-4-hydroxy-4-phenylcyclohexane-1-carboxylate. The molecular and crystal structures of the product were studied by X-ray analysis.     

1-Ethyl-1,4-dihydro-4-oxo-7-(pyridinyl)-3-quinolinecarboxylic acids. I. Synthesis of 3- and 4-(3-aminophenyl)pyridine intermediates

A series of substituted 3- and 4-(3-aminophenyl)pyridines has been prepared as intermediates for the synthesis of some 1-alkyl-1,4-dihydro-4-oxo-7-pyridinyl-3-quinolinecarboxylic acids. The Hantzsch, Hauser and other pyridine syntheses were used. 4-(3-Aminophenyl)pyridine was prepared via 3-(4-pyridinyl)-2-cyclohexen-1-one using the Semmler-Wolff reaction.     

X-Ray Crystallography of 3-(2-0-Acetyl-1, 3-Dibromo-1, 3-DI-Deoxy-L-Erythro-Glycerol-I-YL)-l-Phenyl-2-Pyrazoline-4, 5-Dione 4-(Phenylhydrazone)

Abstract

X-Ray crystallography confirmed the L-erythro-config-uration of 3-(2-0-acetyl-1, 3-dibromo-1, 3-dideoxy-glycerol-l-yl)- 1-phenyl-2-pyrazo line-4, 5-dione 4 -(phenylhydrazone) that results from the reaction of hydrogen bromide in acetic acid with the corresponding of L-threo-glycerol-1-yl- analog.     

Synthesis and characterization of novel 2-(1-benzyl-3-[4-fluorophenyl]-1H-pyrazol-4-yl)-7-fluoro-4H-chromen-4-one derivatives

Novel 1-benzyl-3-(4-fluorophenyl)-1H-pyrazole-4-carbaldehydes 3a to 3e were synthesized via Vilsmeier-Haack reaction of the appropriate 1-benzyl-2-(1-(4-fluorophenyl)ethylidene)hydrazines, derived from 4-fluoroacetophenone 1 with substituted 2-benzylhydrazines 2a to 2e . The base catalyzed condensation of 1-benzyl-3-(4-fluorophenyl)-1H-pyrazole-4-carbaldehydes 3a to 3e with 1-(4-fluoro-2-hydroxyphenyl)ethanone 4 gave (E)-3-(1-benzyl-3-(4-fluorophenyl)-1H-pyrazol-4-yl)-1-(4-fluoro-2-hydroxyphenyl)prop-2-en-1-ones 5a to 5e . On cyclization with dimethyl sulfoxide (DMSO)/I₂, compounds 5a to 5e gave 2-(1-benzyl-3-(4-fluorophenyl)-1H-pyrazol-4-yl)-7-fluoro-4H-chromen-4-ones 6a to 6e . Structures of all novel compounds were confirmed by infrared (IR), proton nuclear magnetic resonance (¹H NMR), carbon nuclear magnetic resonance (¹³C NMR), and mass spectral data. All the synthesized compounds were screened for their antibacterial activities.     

Synthesis of (E)- and (Z)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles

Abstract  

An efficient synthesis method for the preparation of a series of new (Z)- and (E)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles was developed. The reaction of (Z)- and (E)-3-styrylchromones with hydrazine hydrate afforded the corresponding (Z)- and (E)-3(5)-(2-hydroxyphenyl)-4-styrylpyrazoles, except for nitro derivatives, where both (Z)- and (E)-4′-nitro-3-styrylchromones afforded (E)-3(5)-(2-hydroxyphenyl)-4-(4-nitrostyryl)pyrazoles. The reaction mechanism for these transformations is discussed and the stereochemistries of all products were established by NMR experiments.     

Synthesis and anticonvulsant activity of 3-[3-[(dimethylamino)-methyl]-5-methyl-4H-1,2,4-triazol-4-yl]-4-(o-chlorobenzoyl)pyridine

Wolff-Kishner reduction of 3-amino-4-(o-chlorobenzoyl)pyridine ( 3 ) afforded 3-amino-4-(o-chlorobenzyl)pyridine ( 5 ), which on subsequent reaction with triethyl orthoformate and then acetyl hydrazide yielded 1-acetyl-2-[N-[4-(o-chlorobenzyl)pyridin-3-yl]formimidoyl]hydrazone ( 7 ). Cyclization of hydrazone 7 gave 3-(3-methyl-4H-1,2,4-triazol-4-yl)-4-(o-chlorobenzyl)pyridine ( 8 ), which on Jones oxidation yielded 3-(3-methyl-4H-1,2,4-triazol-4-yl)-4-(o-chlorobenzyl)pyridine ( 9 ). The Mannick reaction of 3-(3-methyl-4H-l,2,4-triazol-4-yl)-4-(o-chlorobenzyl)pyridine ( 9 ) with aqueous formalin and dimethylamine hydrochloride afforded 3-[3-[(dimethylamino)methyl]-5-methyl-4H-1,2,4-triazol-4-yl]-4-(o-chlorobenzoyl)-pyridine ( 10 ). 3-[3-[(Dimethylamino)methyl]-5-methyl-4H-1,2,4-triazol-4-yl]-4-(o-chlorobenzoyl)pyridine ( 10 ) exhibited good anticonvulsant activity in the subcutaneous pentylenetetrazole anticonvulsant screen indi cating that an appropriately substituted-pyridine ring moiety can serve as a bioisostere of a chlorobenzene ring with respect to anticonvulsant activity.     

Synthesis of Derivatives of 4-Hydroxy-2-methyl-3-[2-(5-mercapto-1H-1,2,4-triazol-3-yl)ethyl]quinoline and 2-[2-(4-Hydroxy-2-methyl-3-quinolyl)ethyl]-4H-3,1-benzoxazin-4-one

From 4-hydroxy-2-methylquinoline-3-propionyl chlorides hydrochlorides the corresponding thiosemicarbazides were synthesized. The cyclization of the latter both in alkaline and acidic media furnished 4-hydroxy-2-methyl-3-[2-(5-mercapto-1H-1,2,4-triazol-3-yl)ethyl]quinolines. The reaction of the above propionyl chlorides with anthranilic acid afforded the corresponding 2-[2-(4-hydroxy-2-methyl-3-quinolyl)ethyl]-4H-3,1-benzoxazin-4-ones.     

Synthesis and antimycobacterial screening of new 4-(4-(1-benzyl-1H-1,2,3-triazol-4-yl)-1-phenyl-1H-pyrazol-3-yl)quinoline derivatives

A new series of 4-(4-(1-benzyl-1H-1,2,3-triazol-4-yl)-1-phenyl-1H-pyrazol-3-yl)quinoline ( 6a-t ) have been synthesized by a click reaction of 4-(4-ethynyl-1-phenyl-1H-pyrazol-3-yl)quinoline ( 4a-d ) with a substituted benzyl azide ( 5a-e ). The starting alkyne derivatives 4a-d are obtained from Bestmann-Ohira reaction of 1-phenyl-3-(quinolin-4-yl)-1H-pyrazole-4-carbaldehyde and dimethyl(1-diazo-2-oxopropyl)phosphonate. The newly synthesized compounds are screened against M. tuberculosis H37Ra dormant and active, Escherichia coli, Pseudomonas fluorescence, Staphylococcus aureus and Bacillus subtilis strains at 30 μg/mL concentration. Most of the screened compounds showed good to moderate antibacterial activity against S. aureus, B. subtilis, and Mycobacterium tuberculosis H37Ra strains. The synthesized derivatives of quinolinyl-pyrazole-4-carbaldehyde and quinolinyl-pyrazole-4-ethyne reportd good to moderate activity against both strains of M. tuberculosis H37Ra. Ten derivatives of quinolinyl-pyrazole presented good activity against B. subtilis. These results suggested that further optimization and development of quinolinyl-pyrazolyl-1,2,3-triazole moeity could serve as lead compounds for antimycobacterial activity.     

Synthesis and Stereochemistry of (1S,3S,4S,7R11R)-3-(4-Nitrophenyl)-11-aza-2,6-dioxatricyclo[5,3,1,04,11]undecane

The reaction of (1S,2S)-2-amino-1-(4-nitrophenyl)-1,3-propanediol with glutaraldehyde has been studied. It has been established on the basis of AM1 and PM3 calculations and ¹H NMR spectra recorded in the presence of the shift reagent Eu(fod)₃ that (1S,3S,4S,7R,11R)-3-(4-nitrophenyl)-11-aza-2,6-dioxatricyclo[5,3,1,0^4,11]undecane is formed as the result of the reaction.     

Synthese und Reaktionsverhalten von 3-(Bis(alkylthio)methylen)-3H-isobenzofuran-1-on-und 2-(Bis(alkylthio)methylen)-3(2H)-benzofuranon-Derivaten

Summary 3(Bis(alkylthio)methylene)-3H-isobenzofuran-1-ones2a–e and 2-(bis(alkylthio)methylene)-3(2H)-benzofuranone derivatives4a–c are obtained by reaction of phthalides1a–d or 3(2H)-benzofuranone (coumaranone3), respectively, with carbon disulfide under basic conditions followed by alkylation. The reaction behaviour of the new compounds2 and4 is investigated. 2-((2-Dimethylthio-1-oxo)ethyl)benzoic acid N,N-dimethylamide (7a) and 2-((2-dimethylthio-1-oxo)ethyl)-benzoic acid 2-methylpiperidide (7b) are surprisingly formed instead of the methylthio substitution products by treatment of2a with the corresponding amine in the presence of aluminum chloride.

Herrn Professor Dr. Dr. h. c.Waldemar Adam zum 60. Geburtstag gewidmet     

Umsetzungen von 3-(Dimethylamino)-2,2-dimethyl-2H-azirin mit Barbitursäure-Derivaten

Reactions of 3-(Dimethylamino)-2,2-dimethyl-2H-azirines with Barbituric-Acid Derivatives The reaction of 3-(dimethylamino)-2,2-dimethyl-2H-azirine ( 1 ) and 5,5-disubstituted barbituric acids 5 in i-PrOH at ca. 70° gives 2-[5-(dimethylamino)-4,4-dimethyl-4H-imidazol-2-yl]alkanamides of type 6 in good yields (Scheme 1). The formation of 6 proceeds with loss of CO₂; various reaction mechanisms with a zwitterionic 1:1 adduct B as common intermediate are discussed (Schemes 2 and 5). Thermolysis of product 6 leads to 2-alkyl-5-(dimethylamino)-4,4-dimethyl-4H-imidazoles 8 or the tautomeric 2-alkylidene derivatives 8 ′ via elimination of HNCO (Scheme 3). The latter undergoes trimerization to give 1,3,5-triazine-2,4,6-trione. No reaction is observed with 1,5,5-trisubstituted barbiturates and 1 in refluxing i-PrOH, but an N-alkylation of the barbiturate occurs in the presence of morpholine (Scheme 4). This astonishing reaction is explained by a mechanism via formation of the 2-alkoxy-2-(dimethylamino )aziridinium ion H which undergoes ring opening to give the O-alkylated 2-amino-N¹,N¹-dimethylisobutyramide I as alkylating reagent (Scheme 4).     

Chinazolincarbonsäuren. XII. Mitteilung. Synthese von [2-(Ethoxycarbonyl)-3,4-dihydro-4-oxochinazolin-3-yl]-, [2-(Ethoxycarbonyl)chinazolin-4-yloxy]- und (5,6,7,8-Tetrahydro-2-phenylchinazolin-4-ylthio)alkansäure-estern

Quinazolinecarboxylic Acids. Synthesis of Alkyl [2-(Ethoxycarbonyl)-3,4-dihydro-4-oxoquinazolin-3-yl]-, [2-(Ethoxycarbonyl)quinazolin-4-yloxy]- and (5,6,7,8-Tetrahydro-2-phenylquinazolin-4-ylthio)alkanoates The [(2-aminobenzoyl)amino]alkanoic acids and their esters 1 showed a different reaction behaviour with diethyl oxalate. Compound 1 (n = 2,3) was converted into the quinazolinylalkanoates 3 . o-Aminohippurate yielded with ethyl (chloroformyl)formate a mixture of the amide 4 and the cyclized quinazolinone 7b . Ethyl 3,4-dihydro-4-oxoquinazoline-2-carboxylate ( 6 ) reacted with 2-bromoalkanoates, in the presence of NaH, to the [2-(ethoxycarbonyl)-3,4-dihydro-4-oxoquinazolin-3-y1]acetates 7 in the case of alkyl bromoacetate, and to the O-alkylated derivatives 8 with the ethyl 2-bromopropionate and -butyrate. 2-Aminobenzamide ( 5 ) gave with ethyl 3-(chloroformyl)-2-propenoate and methyl 3-(chloroformyl)propionate the amides 9 or 11 , respectively, and not the expected quinazolinones. The cyclized product 12 was obtained from 11 and ethyl bromoacetate. Tetrahydroquinazolin-4(3H)-thione 14 was synthesized by the reaction of 13 with NH₃, and it was alkylated at the S-atom with bromoalkanoates to 15 . The hydrazide 16 was synthesized from 15b with hydrazine hydrate.