Synthesis of Novel Thiazolidin‐4‐ones and Thiazinan‐4‐ones Analogous to Rosiglitazone

This work reports the synthesis of thiazolidin‐4‐ones and thiazinan‐4‐ones analogous to rosiglitazone, a potent antidiabetic drug. The desired compounds were synthesized with moderate to good yields by one‐pot reactions between different primary amines, mercaptoacetic or mercaptopropionic acids, and the 4‐(2‐(methyl(pyridin‐2‐yl)amino)ethoxy)benzaldehyde. The cyclocondensation reactions were carried out for 20 h, and all the products were characterized by ¹H and ¹³C nuclear magnetic resonance spectroscopy, mass spectrometry, and one example by X‐ray diffraction.     

Synthesis and biological activities of 2‐alkylthio‐5‐furylmethylidene‐4H‐imidazolin‐4‐ones

Novel 2‐alkylthio‐5‐furylmethylidene‐4H‐imidazolin‐4‐ones 4 have been synthesized via tandem aza‐ Wittig reaction. The structures were determined by ir, nmr, mass spectroscopy, and elemental analysis. They were screened for fungicidal activities against Fusarium oxysporium, Botryosphaeria berengeriana and Rhizoctonia solani, and growth inhibition of Barnyard grass and Cole root and stalk. A few of them possess significant biological activities.     

Synthesis of 2,3‐dihydro‐1,3‐thiazin‐4(1H)‐ ones and their remarkably facile recyclization to 2,3‐dihydropyrimidin‐4(1H)‐ones

Functionalized 2,3‐dihydro‐1,3‐thiazin‐4(1H)‐one derivatives have been synthesized by cyclocondensation of 3‐alkyl(aryl)amino‐2‐cyano‐3‐mercaptoacrylamides with aldehydes and ketones under acidic catalysis. 6‐Alkyl(aryl)amino‐5‐cyano‐2,3‐dihy‐ dro‐1,3‐thiazin‐4(1H)‐ones, when treated with a dilute solution of potassium hydroxide, are converted into the potassium salts of isomeric compounds, 1‐alkyl‐ (aryl)‐5‐cyano‐6‐mercapto‐2,3‐dihydropyrimidin‐ 4(1H)‐ones. Alkylation of the latter with dimethyl sulfate in situ furnishes 1‐alkyl(aryl)‐6‐alkylthio‐5‐ cyano‐2,3‐dihydropyrimidin‐4(1H)‐ones, whereas boiling them in ethanol with an excess of hydrochloric acid leads to starting 2,3‐dihydro‐1,3‐thiazin‐4(1H)‐ones. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:426–436, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20129     

One‐Pot Synthesis of Pyrrolo[1,2‐a]quinolin‐1‐ones by the Cyclocondensation of 5‐Hydroxy‐1‐arylpyrrolidin‐2‐ones with Dicarbonyls

A one‐pot synthesis of pyrrolo[1,2‐a]quinolin‐1‐ones has been developed from the reactions of 5‐hydroxy‐1‐arylpyrrolidin‐2‐ones with 1,3‐dicarbonyl compounds under the promotion of H₃PO₄/P₂O₅ or HOAc/H₂SO₄. The pyrrolo[1,2‐a]quinolin‐1‐ones are formed by two‐step reactions, that is, the coupling of N‐acyliminium ion intermediates produced from 5‐hydroxy‐1‐arylpyrrolidin‐2‐ones with 1,3‐dicarbonyls and subsequent Friedel–Crafts reactions of the resulting ketone with the aryl ring.     

Rhodium(I)‐Catalyzed Reductive Cyclocarbonylation of Internal Alkynes: Atom‐Economic Process for Synthesis of 2‐Cyclopenten‐1‐ones, 5‐Alkylidenefuran‐2(5 H)‐ones and Indan‐1‐ones

Economical atoms : 2‐Cyclopenten‐1‐ones, 5‐alkylidenefuran‐2(5 H)‐ones and indan‐1‐ones have been synthesized by atom‐economic reductive cyclocarbonylation of internal alkynes with carbon monoxide catalyzed by [{RhCl(CO)₂}₂]/CO(NH₂)₂ in the presence of water (see scheme).

     

Quinolone analogues 6 [1‐5]. Synthesis of 3‐halogeno‐1‐methylpyridazino[3,4‐b]quinoxalin‐4(1H)‐ones

The reaction of the quinoxaline N‐oxides 7a,b with diethyl ethoxymethylenemalonate gave the 1‐methylpyridazino[3,4‐b]quinoxaline‐4,4‐dicarboxylates 8a,b , whose reaction with N‐bromosuccinimide or N‐chlorosuccinimide afforded the 3‐halogeno‐1‐methylpyridazino[3,4‐b]quinoxaline‐4,4‐dicarboxylates 9a‐d. The reaction of compounds 9a‐d with hydrazine hydrate resulted in hydrolysis and decarboxylation to provide the 3‐halogeno‐1‐methylpyridazino[3,4‐b]quinoxaline‐4‐carboxylates 10a‐d , whose reaction with nitrous acid effected oxidation to furnish the 3‐halogeno‐4‐hydroxy‐1‐methylpyridazino[3,4‐b]quinoxaline‐4‐carboxylates 11a‐d , respectively. The reaction of compounds 11a‐d with hydrazine hydrate afforded the 3‐halogeno‐1‐methylpyridazino[3,4‐b]quinoxalin‐4‐ols 12a‐d , whose oxidation provided the 3‐halogeno‐1‐methylpyridazino[3,4‐b]quinoxalin‐4(1H)‐ones 6a‐d , respectively. Compounds 6a‐d had antifungal activities in vitro.     

Eco‐friendly and Efficient Synthesis of 2,3‐Dihydroquinazolin‐4(1H)‐ones

A simple and facile method for the synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones through the direct cyclocondensation of one‐pot three‐component cyclocondensation of isatoic anhydride, ammonium acetate (or primary amines) and aldehydes; and anthranilamide and aldehydes using silica supported ferric chloride (SiO₂‐FeCl₃) as catalyst under solvent‐free conditions is described.     

3‐(α‐Chlorobenzyl)quinoxalin‐2(1H)‐ones as Versatile Reagents for the Synthesis of 3‐Benzylquinoxalin‐2(1H)‐ones and Thiazolo[3,4‐a]quinoxalin‐4(5H)‐ones

Facile and efficient methods for the synthesis of 3‐benzylquinoxalin‐2(1H)‐ones and thiazolo[3,4‐a]quinoxalin‐4(5H)‐ones by the reaction of the readily available 3‐(α‐chlorobenzyl)quinoxalin‐2(1H)‐ones and thiourea have been developed, with multiple roles of the latter. Possible mechanisms are discussed. These two‐step sequences can be performed in a one‐pot manner to produce the desired products in moderate to high yields.     

Reactions of 4‐Hydroxyquinolin‐2(1H)‐ones with Acenaphthoquinone: Synthesis of New 1,2‐Dihydroacenaphthylene‐spiro‐tetrakis(4‐hydroxyquinolin‐2(1H)‐ones)

Reaction of four equivalents of 4‐hydroxyquinolin‐2(1H)‐ones with one equivalent of acenaphthoquinone in absolute ethanol, containing catalytic triethylamine, gave 3,3′,3″,3?‐(1,2‐dihydroacenaphthylene)‐1,1,2,2‐tetrayl‐tetrakis(4‐hydroxyquinolin‐2(1H)‐ones) in a good to excellent yields. The structures of the products were elucidated by ¹H NMR, ¹³C NMR, NMR, IR, mass spectra, and elemental analyses.     

Synthesis and reactions of 2‐hetero‐4H‐3,1‐benzoxazin‐4‐ones

The present review covers the synthesis and reactions of 2‐hetero‐4H‐3,1‐benzoxazin‐4‐ones which include oxygen, sulfur and nitrogen substituents. Literature coverage includes publications primarily from the mid 1960's to December 1999.     

Synthesis of Some New Heteroylhydrazono‐1,3‐thiazolidin‐4‐ones

A series of (Z)‐methyl‐2‐[(Z)‐3‐substituted‐4‐oxo‐2‐(2‐picolinoyl‐/thiophene‐2‐carbonyl)‐hydrazonothiazolidin‐5‐ylidene]acetates were synthesized by condensation N‐substituted‐(2‐picolinoyl‐, thiophene‐2‐carbonyl)hydrazinecarbothioamides with dimethylacetylenedicarboxylate. The structure of thiazolidin‐4‐one derivatives has been confirmed unambiguously by single crystal X‐ray crystallography.     

An Efficient Synthesis of Thiazolidine‐4‐ones with Antitumor and Antioxidant Activities

Reaction of 3‐aroyl‐1‐arylthioureas with dimethyl but‐2‐ynedioate in dichloromethane and catalyzed by triphenylphosphine at ?5°C led to (Z)‐methyl 2‐[(Z)‐2‐(4‐aroylimino)‐4‐oxo‐3‐aryl‐1,3‐thiazolidin‐5‐ylidene]acetates in good yields. The mechanism is discussed. X‐ray structure analysis of one thiazolidine derivative is described. Antitumor and antioxidant activities have been investigated. One derivative of 1,3‐thiazolidine showed moderate antiproliferative in vitro activity against hepatocellular carcinoma Hep‐G2, whereas another 1,3‐thiazolidine introduced effective antioxidant activity compared to ascorbic acid.     

Synthesis and structure of substituted 5‐phenoxy‐1,2,4‐dithiazole‐3‐ones

Seven new substituted 5‐phenoxy‐1,2,4‐dithiazole‐3‐ones were prepared in modest yield (53–76%) from corresponding O‐phenyl thiocarbamates and chlorocarbonylsulfenyl chloride in dry ether at ?10 °C. All of the compounds were characterized by NMR and elemental analysis and some of them by X‐ray diffraction. Preliminary kinetic measurements showed that the parent 5‐phenoxy‐1,2,4‐dithiazole‐3‐one is a very efficient sulfurizing agent toward triphenyl phosphite. J. Heterocyclic Chem., (2011)     

Synthesis of Novel Heterocycles Derived from 4‐Arylmethylene‐2‐phenyl‐1,3‐oxazole‐5(4H)‐ones

The acid hydrazide derivatives 2 were converted into pyrazolone, triazinone, and schiff bases. However, the reaction of Schiff base 12 with malononitrile or thioglycolic acid gives the pyrazolotriazinone or thiazolidinone derivative, respectively. The structures of the newly synthesized compounds were established on the basis of IR, ¹H‐NMR, mass spectral data, and elemental analyses. The antimicrobial activities of the synthesized compounds were examined against two types of bacteria and two types of fungi. Some of the tested compounds showed promising activities.     

An Efficient Synthesis of 4‐Arylmethylidene‐3‐substituted‐Isoxazol‐5(4H)‐ones in Aqueous Medium

A series of 4‐arylmethylidene‐3‐substituted‐isoxazol‐5(4H)‐ones were efficiently synthesized by eco‐benign, one pot uncatalyzed reaction of β‐keto‐ester, hydroxylamine hydrochloride, and aromatic aldehyde with electron donating substituent in water.     

Synthesis and Herbicidal Activity of Novel 4‐Acyl‐2,5‐disubstituted‐3‐hydroxypyrazoles and 4‐Arylcarbonyl‐3‐substitutedisoxazol‐5‐ones

Two series of novel 4‐acyl‐2,5‐disubstituted‐3‐hydroxypyrazoles 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h and 4‐arylcarbonyl‐3‐substitutedisoxazol‐5‐ones 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i were synthesized by the Scotton–Baumann reaction of 2,5‐disubstituted‐2,4‐dihydro‐pyrazol‐3‐ones 1 or 3‐substituted‐4H‐isoxazol‐5‐ones 6 and various acyl chlorides, followed by the Fries rearrangement in the presence of calcium hydroxide and calcium oxide as the catalyst. Their structures were confirmed by IR, ¹H NMR, mass spectroscopy, and elemental analyses. ¹H NMR indicated that compounds 3 existed in enol forms and compounds 7 in keto configurations. The results of preliminary bioassays showed that some of the title compounds 3 and 7 exhibited moderate to good herbicidal activities against Brassica campestris L. at the concentration of 100 mg/L. Isoxazole compounds 7 showed better herbicidal activity against B. campestris L. than pyrazole compounds 3 did at the concentration of 100 mg/L. Moreover, most of the isoxazole compounds displayed higher herbicidal activity against B. campestris L. than Echinochloa crus‐galli. However, these compounds showed weak herbicidal activities at the concentration of 10 mg/L.     

New routes to 1‐functionally substituted arylbenzotriazoles: 3‐Benzotriazol‐1‐yl‐pyridazine‐4‐ones, 5‐benzotriazol‐1‐yl‐pyridazine‐6‐ones and 5‐benzotriazol‐1‐yl‐pyridazine‐6‐imines

Condensation of 1‐arylhydrazono‐1‐benzotriazol‐1‐yl 2‐propanones ( 5a‐c ) with DMF DMA afforded 1‐aryl‐3‐benzotriazol‐1‐yl‐1,4‐dihydropyridazine‐4‐ones ( 8a‐c ). While condensation of 1‐functionally substituted methylbenzotriazoles 3b,c with 2‐arylhydrazono‐3‐oxoarylpropanal 13a,b give 3‐aroyl‐5‐(benzo‐triazolyl‐1‐yl)‐1,6‐dihydro‐1‐phenylpyridazine‐6‐ones and 6‐imines 14a‐d.