Novel Synthesis of Isoquinoline Derivatives Derived from (Z)-4-(1,3-Diphenylpyrazol-4-yl)isochromene-1,3-dione

A series of isoquinoline derivatives were synthesized via the reaction of the (Z)-4-(1,3-diphenylpyrazol-4-yl)isochromene-1,3-dione with different hydrazides, primary amines, diamines, 2-aminothiophenol, 2-aminobenzoic acid, p-aminoacetophenone, and ethyl 2-amino-4,5,6,7-tetrahydrobenzo-[b]thiophene-3-carboxylate. All the synthesized compounds were characterized by infrared, ¹H NMR, and mass spectra besides the analytical data.     

A One‐Pot Synthesis of 1,2‐Dihydroisoquinoline Derivatives from Isoquinoline via a Four‐Component Reaction

A four‐component reaction for the synthesis of 1,2‐dihydroisoquinoline derivatives is described. The Huisgen 1,4‐dipolar intermediate, which is produced from isoquinoline and an electron‐deficient acetylene compound 1 , reacts with H₂O in the presence of diketene to produce 1,2‐dihydroisoquinoline derivatives 2 (Scheme 1). In addition, reaction of isoquinoline, dibenzoylacetylene (=1,4‐diphenylbut‐2‐yne‐1,4‐dione), and diketene in the presence of H₂O leads to pyrroloisoquinoline derivative 7 . The structures of the compounds 2a – f and 7 were corroborated spectroscopically (IR, ¹H‐ and ¹³C‐NMR, EI‐MS) and by elemental analyses. A plausible mechanism for the reaction is proposed (Schemes 2 and 3).     

One‐Pot Synthesis of 6,7‐Fused Steroidal Thiazoles in Cholestane Series

A convenient one‐pot synthesis of 2′‐amino‐ and 2′‐N‐phenylamino‐5α‐cholest‐6‐eno[6,7‐d]thiazole derivatives 4 ‐ 9 are reported. The synthesis involves the reaction of cholestan‐6‐ones 1 ‐ 3 with thiourea or phenylthiourea and iodine. The products have been characterized on the basis of IR, ¹H‐NMR and Mass, which find support in two cases from comparison with authentic samples.     

High Yield One‐Pot Synthesis of Some Novel N‐Methyl Isoxazolidine Derivatives Using N‐Methyl‐α‐chloro Nitrone in Water

A simple one pot and high yield efficient method is described in water for the diastereo and regioselective synthesis of some novel isoxazolidine derivatives at room temperature in a short reaction time.     

A Novel One‐Pot Method for the Synthesis of Pyrimidine Derivatives Using Ketene N,S‐Acetal with Aryl Aldehydes

A very simple and facile one‐pot method for the synthesis of pyrimidine derivatives is presented. In this method, 2‐aryl‐pyrimidine derivatives were prepared by the reaction of ketene N,S‐acetal 1 with commercially available aryl aldehydes by heating under solvent and catalyst‐free conditions. The synthesized pyrimidine derivatives showed blue‐green fluorescence in solid state.     

One‐Pot Synthesis of 2‐Arylbenzoxazoles Promoted by Heteropolyacids

Benzoxazole derivatives were obtained in high yields with excellent purity from the condensation of 2‐aminophenol with benzaldehydes and benzoic acids in the presence of a catalytic amount of heteropolyacids (HPAs).     

One‐Pot Stereoselective Synthesis of 2‐Acylaziridines and 2‐Acylpyrrolidines from N‐(Propargylic)hydroxylamines

The stereoselective direct transformation of N‐(propargylic)hydroxylamines into cis‐2‐acylaziridines was achieved by the combined use of AgBF₄ and CuCl. Copper salts were found to promote the transformation of the intermediary 4‐isoxazolines into 2‐acylaziridines and both 3‐aryl‐ and 3‐alkyl‐substituted 2‐acylaziridines could be prepared by using this method. Furthermore, subsequent 1,3‐dipolar cycloaddition of azomethine ylides that were generated in situ from the intermediary 2‐acylaziridines with maleimides was achieved in a stereoselective one‐pot procedure to afford the corresponding 2‐acylpyrrolidines, which consisted of an octahydropyrrolo[3,4‐c]pyrrole skeleton.     

Gold Catalysis: One‐Pot Alkylideneoxazoline Synthesis/Alder‐Ene Reaction

Based on the gold‐catalyzed synthesis of methyleneoxazolines, a one‐pot combination with an Alder‐ene reaction was developed. For azodicarboxylates, good to very good yields (51–99 %) of the oxazolemethylhydrazinedicarboxylates were achieved with 3 mol % of the Gagosz catalyst, [Ph₃PAuNTf₃]. In a less‐selective reaction, 4‐phenyl‐3H‐1,2,4‐triazol‐3,5(4 H)‐dione gave lower yields (41–49 %) of the corresponding oxazolemethylphenyltriazolidinediones. Overall, five new bonds were formed. Tetracyanoethylene afforded a cyclobutane derivative through a [2+2] cycloaddition reaction at ?40 °C, but only 45 % of the spiro compound was obtained. The less‐readily available KITPHOS ligands on gold gave even higher yields at lower catalyst loadings (2 mol %), but longer reaction times were required.     

Microwave Promoted,Sodium Acetate Catalyzed One Pot Synthesis of Poly Functionalized 4H‐Pyrans

A clean and efficient one pot synthesis of 4H‐pyran derivatives through condensation of aromatic aldehydes, malononitrile and dicarbonyl compounds under microwave irradiation in presence of Sodium acetate as a catalyst is described.     

One‐Pot Synthesis of Pyrazoles through a Four‐Step Cascade Sequence

A one‐pot synthesis of 3,4,5‐ and 1,3,5‐pyrazoles from tertiary propargylic alcohols and para‐tolylsulfonohydrazide has been accomplished. The pyrazoles are formed through a four‐step cascade sequence, including FeCl₃‐catalyzed propargylic substitution, aza‐Meyer–Schuster rearrangement, base‐mediated 6π electrocyclization, and thermal [1,5] sigmatropic shift. In this reaction, the 3,4,5‐ and 1,3,5‐pyrazoles are produced selectively according to different substituents in the starting alcohols.     

A Novel One‐Pot Synthesis of Substituted Quinolines

A synthesis of quinoline derivatives is described via reaction between ethyl bromopyruvate (=ethyl 3‐bromo‐2‐oxopropanoate), acetylenedicarboxylate, and isatin (=1H‐indole‐2,3‐dione) in the presence of NaH as a base. Also, these reactions were performed without ethyl bromopyruvate. The reaction in the presence of ethyl bromopyruvate provides regioselectively a quinoline with the ethyl ester group in 4‐position. In the absence of ethyl bromopyruvate, the reaction leads to functionalized quinolines with the same ester groups in 2‐, 3‐, and 4‐positions.     

Iron‐Promoted Practical One‐Pot Synthesis of 2,5‐Disubstituted Oxazoles

A practical one‐pot protocol for the synthesis of 2,5‐disubstituted oxazoles from 1‐aryl‐2‐nitroethanones was reported. In the presence of iron/AcOH in acetonitrile, the reaction of 1‐aryl‐2‐nitroethanones with trimethyl orthoacetate or trimethyl orthobenzoate delivered the corresponding 2,5‐disubstituted oxazoles in moderate to good yields.     

One‐Pot Three‐Component Synthesis of Oxazine Derivatives in Water

A one‐pot synthesis of oxazine derivatives via reaction between activated acetylenic compounds, benzoyl cyanide, and N‐nucleophiles in water as the solvent is described?.     

Novel Method of Synthesizing Various Five Membered Heterocycles from an Aryl Tribromomethyl Group

Synthesis of five membered heterocycles from an aryl tribromomethyl functional group is discussed. Exposing a tribromomethyl group to subsequent nucleophilic attacks by a 1,2-di-nucleophilic species promotes the cyclization of five membered heterocycles. Such heterocycles as oxadiazoles, thiadiazole, benzimidazole, benzothioazole, and benzoxazole were synthesized in moderate to good yields.

Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file.     

Highly Regioselective and Diastereoselective,One‐Pot,Four‐Component Synthesis of Novel Spiroindenoquinoxalineindolizidine Derivatives

A one‐pot, four‐component procedure for the synthesis of novel spiroindenoquinoxalineindolizidines with high regioselectivity and diastereoselectivity from the 1,3‐dipolar cycloaddition of azomethine ylides, generated from indenoquinoxalines and pipecolinic acid, and chalcones is described. The reaction occurs under reflux of ethanol as a green solvent and in the absence of any catalyst. The cycloadducts are obtained purely without future purification. The regiochemistry and stereochemistry of resultant cycloadducts have been determined by several 2D‐NMR spectroscopic techniques and X‐ray single crystal diffraction.     

Efficient and Facile Catalyst‐free One‐Pot Synthesis and Characterization of Some Novel Bis(2‐benzothiazole) Derivatives

A general method for preparation of benzothiazole derivatives including oxidative cyclization of the corresponding Schiff bases was reported. Herein, we have been synthesized a series of new acyclic‐substituted bis(2‐arylbenzothiazoles). Synthesis of analogs substituted in the benzothiazole ring was achieved via the direct condensation reaction of o‐aminothiophenol with some of dialdehyde compounds under catalyst free in high yields. The structure of these products has been fully characterized by physical and spectroscopic data such as IR, ¹H‐NMR, ¹³C‐NMR, UV‐Vis, MS, and CHN analysis.     

An Efficient One‐Pot Synthesis of New Coumarin Derivatives as Potent Anticancer Agents under Microwave Irradiation

An efficient and rapid synthesis of coumarin derivatives was accomplished via reactions of 3‐(3‐(4‐methoxyphenyl)acryloyl)‐2H ‐chromen‐2‐one ( 3 ) with different carbon nucleophiles such as ethyl acetoacetate, ethyl cyanoacetate, malononitrile, and ethyl benzoylacetate via conventional heating and microwave irradiation conditions and were used as source of pyran and pyridine derivatives bearing coumarin moiety 4 – 11 . Compound 9a was condensed with different carbon electrophiles triethylorthoformate, phenylisothiocyanate, carbon disulfide, benzoylchloride, and acetylchloride that afforded the corresponding chromen derivatives 12 – 16 . All the newly synthesized compounds were characterized by elemental and spectroscopic evidences. All of synthesized compounds were tested for in vitro cytotoxicity. The preliminary screening results showed that most of the compounds had moderate cytotoxic activity against HCT‐116 and MCF‐7 cell lines. Nevertheless, compound 10 exhibited potent activity against the two cell lines, which was comparable with the standard drug 5‐fluorouracil.