An interesting cyclization of N‐methyl‐3‐phenyl‐N‐(2‐(Z)‐phenylethenyl)‐cis‐oxiranecarboxamide

Under Lewis acid condition, N‐methyl‐3‐phenyl‐N‐(2‐(Z)‐phenylethenyl)‐cis‐oxiranecarboxamide undergoes elegant double cyclizations to give interesting products.     

Highly efficient intramolecular cyclizations of 2′‐hydroxychalcones to 4‐chloro‐2H‐chromenes under vilsmeier conditions

Highly efficient intramolecular cyclization and of 2′‐hydroxychalcones to 4‐chloro‐2H‐chromenes under Vilsmeier conditions have been developed. In comparison with the reported methods, studies carried out indicate that Vilsmeier reagent generated in situ from DMF and bis(trichloromethyl) carbonate (BTC) provides excellent chemselectivity, higher yields and avoids the formation of inorganic phosphorus salts.     

Synthesis of an 4‐oxo‐1,4‐dihydropyridinomethylidene substituted 2‐indolinone

The (Z)‐3‐substituted 2‐indolinone 6 was prepared using the aldehydes 4 and 8 unknown up to now and 2‐indolinone.     

Synthesis of some 3‐aryl‐1H‐isochromene‐1‐thiones

A rapid microwave‐accelerated thionation of some 3‐substitued isocoumarins to corresponding 1‐thio‐isocoumarins was achieved employing Lawesson's reagent under solventless conditions.     

1,3‐dipolar cycloadditions. Part XII ‐ selective cycloaddition route to 4‐nitroisoxazolidine ring systems

Cycloadditions of C,N‐diarylnitrones to β‐nitrostyrenes occurred to yield two diastereoisomeric cycloadducts, the 3,4‐trans‐4,5‐trans substituted isoxazolidine derivatives being formed selectively as the major products. These were characterised by spectroscopic and X‐ray data. Conformational studies were carried out by X‐ray crystallography and Molecular Modelling.     

Synthesis of 4‐amino‐5,6,7,8‐tetrahydrothieno[2,3‐b]quinolin‐5‐ol derivatives

This paper describes the synthesis of 4‐amino‐5,6,7,8‐tetrahydrothieno[2,3‐b]quinolin‐5‐ol derivatives ( 3a‐h ) and 4‐amino‐5,6,7,8‐tetrahydrothieno[2,3‐b]quinoline ( 8a ) in good yield by three‐step procedures starting from 2‐aminothiophene‐3‐carbonitrile and 5‐substituted cyclohexane‐1,3‐dione.     

Synthesis of a novel class of 3‐(2′‐benzothiazolyl)‐2,3‐dihydroquinazolin‐4(1H)‐ones under solvent‐free and catalyst‐free conditions

A solvent‐ and catalyst‐free one‐pot three‐component condensation reaction approach was developed for the synthesis of a new class of 3‐(2′‐benzothiazolyl)‐2,3‐dihydroquinazolin‐4(1H)‐ones in relatively good yields.     

The synthesis of a linear tröger's base derived from naphthalene: 7H‐15H‐6,14‐methanodinaphtho[2,3‐b:2′,3′‐f][1,5]diazocine

The title compound 3 was prepared in four steps from commercial 3‐amino‐2‐naphthoic acid in an overall 75 % yield. Attempts to use the same approach in the case of 2‐aminonicotinic acid methyl ester failed. All the compounds were characterized by NMR.     

Synthesis of alicyclic N‐substituted 1,3‐amino alcohols via 1,3‐oxazines

Alicyclic N‐substituted 1,3‐amino alcohols 13‐18 were prepared in a facile way in a one‐pot procedure from 1,3‐oxazines 5‐8 in the presence of a ketone 9‐12 . The complex reaction involves palladium‐catalyzed reduction, debenzylation and/or transimination and further reduction.     

Synthesis of 2,4‐difuryl‐4H‐3,1‐benzothiazines via a furan ring migration reaction

A new simple synthetic approach to 2,4‐difuryl‐4H‐3,1‐benzothiazines from 2‐isothiocyanoaryldifuryl‐methanes in the presence of acidic catalyst is described. This rearrangement is a new example of furan ring migration reaction resulting from intramolecular attack with electrophilic carbon.     

An efficient synthesis of pyrazolo[3,4‐b]pyrrolo[2,3‐d]pyridines from 5‐aminopyrazoles and cyclic β‐keto ester

5‐Chloroethylpyrazolo[3,4‐b]pyridines were synthesized by condensation of 5‐aminopyrazoles with α‐acetyl γ‐butyrolactone followed by cyclization treating with phosphorous oxychloride. 5‐Chloroethyl‐pyrazolo[3,4‐b]pyridines, thus obtained, were then converted to the corresponded tricyclic pyrazolo[3,4‐b]‐pyrrolo[2,3‐d]pyridines by treating with some primary amines.     

Utility of 2‐[4‐(3‐oxobenzo[f]‐2H‐chromen‐2‐yl)‐1,3‐thiazol‐2‐yl]ethanenitrile in heterocyclic synthesis

Pyrazolo[4,3‐d]pyrimidines, pyrazolo[4,3‐d]triazolino[4,3‐a]pyrimidines, 3‐(2‐thiazolyl)thiophenes, thiazolo[3,2‐a]pyridine and pyrazolo[1,5‐a]pyrimidines were synthesized from 2‐[4‐(3‐oxobenzo[f]‐2H‐chromen‐2‐yl)‐1,3‐thiazol‐2‐yl]ethanenitrile. The newly synthesized compounds were elucidated by elemental analysis, spectral data, chemical transformation and alternative synthesis route whenever possible.     

Green and high efficient synthesis of triaza‐benzo[b]fluoren‐6‐one derivatives in water under microwave irradiation

Triaza‐benzo[b]fluoren‐6‐one derivatives were synthesized via the three‐component reaction of aldehyde, cyclohexane‐1,3‐dione compound and 2‐aminobenzimidazole in water under microwave irradiation. The new protocol has the advantages of excellent yield, low cost, reduced environment impact, wide scope and convenient procedure.     

An efficient and greener approach to the synthesis of 3,5‐dicyanopyridin‐2(1H)‐one derivatives in aqueous media under microwave irradiation conditions

A facile and greener synthesis of a series of 3,5‐dicyanopyridin‐2(1H)‐one derivatives was accomplished via the one‐pot reaction of aldehyde, malononitrile and sodium hydroxide in aqueous media under microwave irradiation. This method had several advantages such as shorter route and time, lower cost, reduced environmental impact.     

Synthesis of 2‐substituted benzimidazoles by iodine‐mediated condensation of orthoesters with 1,2‐phenylenediamines

Iodine was found to be an efficient catalyst for the synthesis of 2‐substituted benzimidazoles by the condensation of orthoesters and 1,2‐phenylenediamines in good to excellent yields under mild reaction conditions.