A practical approach to new (5Z) 2-alkylthio-5-arylmethylene-1-methyl-1,5-dihydro-4H-imidazol-4-one derivatives

A practical protocol for the preparation of (5Z)-2-alkylthio-5-arylmethylene-1-methyl-1,5-dihydro-4H-imidazol-4-one derivatives is reported. The new compounds were obtained in good yield and stereoselectivity in two steps, namely a solvent-free Knoevenagel condensation under microwave irradiation, followed by an S-alkylation reaction with various halogenoalkanes.     

Synthesis and antimicrobial activities of some novel substituted 2-imidazolyl-N-(4-oxo-quinazolin-3(4H)-yl)-acetamides

Several substituted-quinazolin-3(4H)-ones 8-11ad were synthesized by condensation of 2-chloro-N-(4-oxo-substituted-quinazolin-3(4H)-yl)-acetamides with various substituted imidazoles through one pot reaction. Elemental analysis, IR, (1)H-NMR and mass spectral data confirmed the structure of the newly synthesized compounds. Synthesized quinazolin-4-one derivatives were investigated for their antitubercular, antibacterial and antifungal activities. Some of the tested compounds showed good antitubercular activity. None of the synthesized compounds showed significant antibacterial and antifungal activity.     

UV absorption spectra and reactivity of 4-oxo and 4-thioxo derivatives of 1,3-thiazane

The C=O groups in positions 4 of the molecules of 2-thioxo-1, 3-thiazan-4-one and 1,3-thiazane-2,4-dione do not possess ketonic properties. When 2-thioxo-1,3-thiazan-4-one is treated with hydrazine or its derivatives, hydrazinolysis takes place. When these substances react with P₂S₅, the C=O groups are replaced by C=S groups. The compounds formed possess thioketonic properties, which makes it possible to obtain derivatives of 4-imino-1,3-thiazane. The condensation of -chloropropionic acid with thiourea leads to 1,3-thiazane-2,4-dione and the previously unreported 2-imino-1,3-thiazan-4-one. The UV spectra of the substances synthesized are described.     

A one-pot synthesis of isoindolin-1-imine derivatives

A one-pot procedure was developed for the synthesis of isoindolin-1-imine derivatives by a simple three-component condensation of 2-cyanobenzaldhyde, ammonium acetate, and 4-hyroxycoumarin derivatives or 1,3-dicarbonyl compounds or 4-hydroxyquinolin-2(1H)-one in ethanol under reflux for 20–60 min with excellent yields. The advantages of this procedure are operational simplicity, excellent yields, and short reactive time, without catalyst, easy workup, and green environmental impact.     

4-Thionazolidones,derivatives and analogs

A hitherto unknown isomer of rhodanine, 4-thiothiazolid-2-one (isorhodanine), is prepared by boiling thiazolidine-2, 4-dione with P₂S₅ in anhydrous dioxane for 3 hr. Isorhodanine I is characterized by great reactivity of the methylene and thione groups. The 4-phenylhydrazone and 4-phenylimino derivatives of I are prepared, as well as condensation products obtained by condensing I with aromatic aldehydes and diazonium salts. 5-Methylisorhodanine is also prepared. A derivative of I containing a quinoline ring is further obtained by reacting I with anthranilaldehyde.For Part II see [2].     

Novel,Simple, and Efficient Synthesis of 3-(2-(5-(Benzylideneamino)-3-phenyl-1H-pyrazol-1-yl)thiazol-4-yl)-4-hydroxy-6-methyl-2H-pyran-2-one Derivatives via a One-Pot,Four-Component Condensation Reaction

The synthesis of 3-(2-(5-(benzylideneamino)-3-phenyl-1H-pyrazol-1-yl)thiazol-4-yl)-4-hydroxy-6-methyl-2H-pyran-2-one derivatives was achieved through a one-pot, four-component reaction involving condensation of 3-(2-bromoacetyl)-4-hydroxy-6-methyl-2H-pyran-2-one, thiosemicarbazide, phenacylcyanaide, and various aryl aldehydes in dry alcohol and few drops of acetic acid under reflux condition. This four-component reaction has some advantages such as ease of handling, good yields, and easy workup. All structures of newly prepared compounds were confirmed by analytical and spectral data.     

Condensation of 2H-indazole-4,7-dione derivatives with 2-aminophenol derivatives

A new type of 9-substituted-5-methyl-2-phenyl-4H-pyrazolophenoxazin-4-one derivatives was prepared by the condensation of 5-methyl- and 6-methyl-2-phenyl-2H-indazole-4,7-diones with 4-substituted-2-aminophenols in pyridine. Relative reactivity of 2-aminophenol derivatives in the condensation was studied.     

Ionic Liquid-Mediated Facile Synthesis and Antimicrobial Study of Thiazolo [2,3-b]Benzo[h]Quinazolines and Thiazino[2,3-b] Benzo-[h]Quinazolines

Abstract

8-Methoxy-4-phenyl-3,4,5,6-tetrahydrobenzo[h]quinazoline-2(1H)-thione, obtained by the condensation of 2-benzylidene-6-methoxy-3,4-dihydronapthalene-1(2H)-one with thiourea, on reaction with chloroacetic acid and 3-chloropropanoic acid in the presence of the ionic liquid N-methylpyridinium tosylate furnishes 3-methoxy-7-phenyl-7,10-dihydro-5H- benzo[h]thiazolo[2,3-b]quinazoline-9(6H)-one and 3-methoxy-7-phenyl-5,6,10,11-tetrahydro- benzo[h][1,3]thiazino[2,3-b]quinazoline-9(7H)-one. Further, condensation of the thione with 1,2-dibromoethane and 1,3-dibromopropane yields 3-methoxy-7-phenyl-6,7,9,10-tetrahydro-5 H-benzo[h]thiazolo[2,3-b]quinazoline and 3-methoxy-7-phenyl-5,6,7,9,10,11-hexahydrobenzo [h][1,3]thiazino[2,3-b]quinazoline respectively. Arylidene derivatives have been obtained by two routes. The structures of the cyclized compounds have been established on the basis of elemental analysis and spectroscopic data. The synthesized compounds were screened for antimicrobial activity. Some of the compounds showed promising antimicrobial activities.     

4-Substituted-3,4-dihydro-3-methyl-2H-1,3-benzoxazin-2-ones. III (2,3). Solvolytic-reductive transformation of 4-(2-keto)-benzoxazin-2-ones into oxazin-2-ones

A series of 4-(2-keto-substituted)-3,4-dihydro-3-methyl-2H-1,3-benzoxazin-2-ones 1 (Table I) was synthesized by condensation of 3-alkyl-3,4-dihydro-4-hydroxy-2H-1,3-benzoxazin-2-ones 4 with ketones 5 having active alpha hydrogens. In the presence of alcoholic potassium borohydride, compounds 1 underwent reductive transacylation to give 1,3-oxazin-2-one derivatives 3 (Table III, a,b,c). When the other side of the ketone possessed substituents other than hydrogen, there were always also normal reduction products, i.e., secondary alcohols 2 (Table II) in addition to 3.     

The condensation products of 2,3,6-trisubstituted-1,4-naphthoquinones with 2-aminothiophenol

The 2,6-disubstituted-, 3,6-disubstituted-5H-benzo[a]phenothiazin-5-one derivatives and 7-substituted-benzo[a] [1,4]benzothiazino[3,2-a]phenothiazine derivatives were prepared by the condensation of 2,3,6-trisubstituted-1,4-naphthoquinones with 2-aminothiophenol. The resulting compounds were subjected to reduction, dehalogenation and condensation with aniline. Some of the condensation intermediates were isolated and the reaction mechanism was also investigated.     

2种苯并咪唑衍生物在微波作用下的固相合成

2种苯并咪唑衍生物在微波作用下的固相合成;固相合成;微波辐射;苯并咪唑衍生物     

Acetals of lactams and acid amides 55. Study of reaction of 3-oxopyridine and isoquinolin-3-one derivatives with dimethylformamide diethyl acetal

The reactions of 4-carbamoyl- and 4-cyanopyridin-3-one and 4-cyanoisoquinolin-3-one with DMFA diethyl acetal were studied, and hydrogenated di- and trimethylene derivatives of 2,7-naphthyridine-1,8-dione were synthesized. It was found that O- or N-alkylation reactions of the pyridone fragment of the starting bicyclic compounds take place together with the condensation of the DMFA acetal at the amide amino group or the active methylene unit.For Communication 54, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 215–220, February, 1990.     

Synthesis of <Superscript>131</Superscript>I labeled estrone derivatives and biodistribution studies on rats

Summary The aim of this study is to synthesize novel ¹³¹I labeled estrone derivatives that may have therapeutical potentials on Estrogen Receptor rich tumors. Two radiolabeled estrone derivatives, [¹³¹I]2-iodo-3-methoxy-estra-1,3,5-trien-17-one and [¹³¹I]4-iodo-3-methoxy-estra-1,3,5-trien-17-one were synthesized. Ether amino estrone derivatives were obtained from estrone in three steps by means of diazonium compounds. Tissue distribution studies exhibited receptor-mediated uptake in target organs in female Albino Wistar rats. Maximum uptakes for 2-iodo[¹³¹I]-3-methoxy-estrone are in stomach, pancreas, intestines and uterus. A similar biodistribution profile was obtained for 4-iodo[¹³¹I]-3-methoxy-estrone. However 2-iodo-3-methoxy-estra-1,3,5-trien-17-one has higher uptake in stomach, kidneys, pancreas, and intestines than 4-iodo-derivative.     

Synthesis of new substituted chromen[4,3-c]pyrazol-4-ones and their antioxidant activities

A series of new coumarin derivatives 4 containing a 4-arylbut-3-en-2-one moiety were synthesized by condensation of 3-acetylcoumarin 1 with aryl aldehydes 2 in chloroform in the presence of piperidine. The interactions of 3-formyl-4-chlorocoumarin (3) with nitrogen-containg nucleophiles leading to the corresponding substituted chromen-[4,3-c]pyrazol-4-ones 5 are described. The structures of the obtained compounds were established on the basis of 1D NMR, 2D NMR and IR and further the compounds were evaluated for possible antioxidant activities. The coumarinic chalcone 4a has been found to be the most active (IC?? = 2.07 μM) in this study.     

Synthesis of 4H-benzo[a]phenoselenazin-4-ones as near-ir dyes

The condensation of 2-bromo- or 2, 6-dibromo-4, 8-bis(alkylamino)-1, 5-naphthoquinones with zinc 2-amino-benzeneselenolates gave 1, 5-bis(alkylamino)-4H-benzo[a]phenoselenazin-4-one and the 3- and/or 10-substituted compounds. These phenoselenazone derivatives absorb nearly infrared light and can be used as optical recording media for a laser beam.     

Triphenylphosphine-m-sulfonate/carbon tetrabromide as an easily recoverable catalyst system for the efficient synthesis of xanthene and xanthenone derivatives under solvent-free conditions

A solid complex,readily prepared from commercially available sodium triphenylphosphine-m-sulfonate（TPPMS） and carbon tetrabromide,can be used as an easily recoverable and reusable catalyst system for one-pot condensation of 2-naphthol with aldehydes to construct 14-aryl（alkyl）-14H-dibenzo[a j]-xanthene derivatives and one-pot condensation of 2-naphthol with aldehydes and cyclic 1 3-dicarbonyl compounds to construct 12-aryl（alkyl）-8 9 10 12-tetrahydrobenzo[a]xanthen-11-one derivatives.     

A new green approach for the synthesis of 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-one derivatives using task specific acidic ionic liquid[NMP]H_2PO_4

12-Aryl-8,9,10,12-tetrahydrobenzo[a]xanthene-11-one derivatives were synthesized by a convenient and environmentally benign procedure involving multicomponent condensation reactions of substituted aromatic aldehydes with 2,7-dihydroxynaphthalene/2-naphthols/2,6-dihydroxynaphthlene and cyclic 1,3-dicarbonyl compounds in task specific acidic ionic liquid[NMP]H_2PO_4 at 80 ℃.This protocol has proved to be efficient in terms of good yields,operational simplicity,easy workup,recyclability of reaction medium/catalyst,and short reaction time.     

Synthesis of new 2-pyridinone and thiazole derivatives containing coumarin moiety

Coumarin has shown considerable therapeutic potency because of its versatile biological prosperities. Also, pyridines have been adopted in medicinal chemistry as potent ring. Moreover, several investigations reported the potency of thiazole-containing compounds. So, during this research, new functionalized 2-pyridinone and thiazole derivatives bearing coumarin moiety were aimed to synthesize. Many trials to obtain the 6-amino-2-oxo-pyridine-3,5-dicarbonitriles through the condensation of cyanoacetohydrazone of 3-acetyl coumarin with 2-(arylidene)malononitriles were carried out using different reaction conditions. In all cases, the reaction gave none of the corresponding 2-pyridinone derivatives except the reaction with 2-(benzylidene)-malononitrile afforded product in few yield. Moreover, the reaction of another cyanoacetanilide with the 2-(arylidene)-malononitrile afforded the unexpected arylidene derivatives rather than the expected pyridin-2-one derivatives. Finally, new thiazoles bearing coumarin moiety were synthesized using 3-acetylcoumarin N-(2,4-dimethoxyphenyl)-thiosemicarbazone. Cyclization of thiosemicarbazone derivative with ethyl 2-chloroacetate, chloroacetone or phenacyl bromide afforded in high yields the corresponding derivatives of thiazolidin-4-one, 4-methylthiazole or 4-phenylthiazole, respectively.     

Synthesis of a novel series of 3-substituted [1]benzothieno[3,2-d]pyrimidine derivatives

A series of 3-substituted [1]benzothieno[3,2-d]pyrimidine derivatives has been synthesized as possible antileukemic agents by condensation of methyl 3-(ethoxymethylene)amino-2-benzothiophene carboxylate (II) with a variety of amines to afford the corresponding 3-aryl and 3-alkyl [I]benzothieno[3,2-d]pyrimidin-4(3H)-ones, Ill and IV, respectively. In addition, Mannich reactions of [I]benzothieno[3,2-d]pyrimidin-4(3H)-one (VIII) with formaldehyde and secondary amines gave the expected derivatives, IX. 3-Amino[I]benzothieno[3,2-d]-pyrimidin-4(3H)-one (VI) reacted with substituted aromatic aldehydes in the presence of boron trifluoride to yield the corresponding imines VII.     

Synthesis of benzophenothiazinone derivatives from 2,3,5-trisubstituted-1,4-naphthoquinones with 2-aminothiophenol

The 1-substituted-5H-benzo[2,3-a]phenothiazin-5-one, 4-substituted-5H-benzo[6,5-a]phenothiazin-5-one and 6-substitutedbenzo[a][1,4] benzothiazino[3,2-c]phenothiazine derivatives were prepared by the condensation of 5-substituted-2,3-dichloro-1,4-naphthoquinones with 2-aminothiophenol. Reduction, acetylation and dehalogenation of the resulting compounds were carried out and the structures of the products were inferred from comparison with the authentic compound.