Magdy M. Hemdan

α-Enones in heterocyclic synthesis of indazole, thiazine, chromene and quinoline derivatives with their antimicrobial activities

α-Enones 1a,b react additively with hydrazine hydrate, thiourea, diethyl malonate, malononitrile, as well as ethyl cyanoacetate. Simultaneous cyclisation of the resulting 1:1 adducts yields indazole, thiazine, chromene and quinoline derivatives. The structures of all the synthesised compounds were confirmed by micro analytical and spectral data. The antimicrobial activity of some of the synthesised compounds were tested.

Uses of 1-(3-Cyano-4,5,6,7-tetrahydrobenzo[b]-thiophen-2-yl)-3-dodecanoylthiourea as a Building Block in the Synthesis of Fused Pyrimidine and Thiazine Systems

The reaction of lauroyl isothiocyanate and 2-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-3-carbonitrile was used to synthesize the title compound 2. Compound 2 could serve as the main building block in the synthesis of many target heterocyclic systems. Various fused pyrimidines were synthesized in the reactions of compound 2 with sodium ethoxide, hydrazine hydrate, phenyl hydrazine, ethyl carbazate, thiourea, and/or 2-aminothiophenol. The structures of the synthesized compounds were confirmed by microanalytical and spectral data.

Utility of Phthalimidoacyl Isothiocyanate in Synthesis of Quinazolines, Benzoxazoles, Benzimidazoles, 1,2,4-Triazoles, and Oxatriazepines

Abstract Phthalimidoacyl isothiocyanates 1a,b participated in a wide range of addition–cyclization reactions. Simultaneous or subsequent cyclization of the obtained adducts gave derivatives of quinazoline, benzoxazole, benzimidazole, 1,2,4-triazole, and oxatriazepine. The structures of all the products were confirmed by microanalytical and spectroscopic data. GRAPHICAL ABSTRACT

The Utility of p-N-Succinimidobenzoyl Isothiocyanate in Synthesis of Benzoxazole, Quinazoline, Pyrimidine, 1,2,4-Triazoline, 1,3-Thiazolidine, and Thiourea Derivatives

Reactions of p-N-succinimidobenzoyl isothiocyanate (1) with different nucleophilic reagents afforded adducts. Simultaneous or subsequent cyclization of these adducts gave access to a variety of different heterocycles, including benzoxazole, quinazoline, pyrimidine, 1,2,4-triazoline, 1,3-thiazolidine and others. The structures of the new products were confirmed by their micro-analytical and spectral data. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

Synthesis and Antimicrobial Activities of Some Heterocyclic Systems from 2-Furoyl Isothiocyanate

2-Furoyl isothiocyanate (1) is used as a building block in synthesizing different heterocyclic systems of anticipated biological activities. Thus, isothiocyanate 1 was reacted with different nucleophilic reagents to produce five- and six-membered heterocyclic systems such as 1,2,4-triazoline, thiadiazolidine, quinazoline, benzothiazole, benzoxazole, benzimidazole, thiazolidine, and imidazolidine. The structures of all the synthesized compounds were confirmed by microanalytical and spectral data. The antimicrobial activity of some of the synthesized compounds was tested. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

Synthesis and antimicrobial study of 1,2,4-triazole, quinazoline and benzothiazole derivatives from 1-naphthoylisothiocyanate

1-Naphthoylisothiocyanate (1) is used as a building block in the synthesis of 1,2,4-triazole, quinazoline, benzothiazole and thiourea derivatives. The antimicrobial activity of some of the synthesised compounds was tested.

Synthesis of 1,2,4-triazoles, imidazoles, pyrimidines, quinazolines, 1,3,5-triazines, and 1,3-thiazines from 3-oxo-5,6-diphenyl-2,3-dihydro-pyridazine-4-carbonyl isothiocyanate

3-Oxo-5,6-diphenyl-2,3-dihydropyridazine-4-carbonyl isothiocyanate (1) was reacted with hydrazine hydrate, or phenyl hydrazine, to give 1,2,4-triazole derivatives in a one pot-reaction. However, reaction of 1 with benzoyl hydrazine afforded thiourea derivative that was cyclised to a differently substituted 1,2,4-triazole. Ethyl glycinate reacted with isothiocyanate 1 to give an adduct that was cyclised to imidazolidine derivative. Reaction of 1 with o-aminophenol, o-phenylenediamine or o-aminothiophenol afforded benzoxazole, benzimidazole or benzothiazole derivatives respectively. Reaction of 1 with thioglycolic acid gave 1,3-thiazine derivative, however, when 1 was treated with anthranilic acid a thiourea derivative was obtained which cyclised to a quinazoline derivative. Reaction of 1 with 2-cyanoacetamide or guanidine HCl yielded pyrimidine or triazine derivatives respectively. The structures of all compounds were confirmed by their micro analytical and spectral data.

Hydrazine derivatives and o-benzoylbenzoic acid as a source of phthalazines with their antimicrobial activities

Starting from 2-benzoylbenzoic acid (1) and prototype hydrazine itself or some of its simple congeners produce phthalazin-1(2H)-one derivatives 2a–d. Reactions of 2 with P2S5 or POCl3 gave their thione derivatives 3a–c or the chloro derivative 4 respectively. Further reactions of phthalazines 3 and 4 with hydrazine derivatives afforded their hydrazinyl derivatives 5a–d. Compounds 5a and 5d were used as a precursor to triazolo 6 and pyrazolyl phthalazines 7. The antimicrobial activities of some of the prepared phthalazines were tested.

Multicomponent synthesis of 4-arylidene-2-phenyl-5(4H)-oxazolones (azlactones) using a mechanochemical approach

BackgroundMechano heterocyclic chemistry (MCH) is a recent quickly growing technique in the synthesis of heterocycles and draws the attention of heterocyclic chemists towards the uses of grindstone technique in a solvent free green efficient synthesis of many heterocyclic systems. On the other hand, multicomponent approach has opened the door for the rapid and efficient one-step procedures to synthesize a wide range of complex targets. Azlactones have been reported to exhibit a wide range of pharmaceutical properties including immune suppressive, anticancer. Antimicrobial, antitumor, anti-inflammatory and antiviral. It also used as useful synthons in the synthesis of several small molecules, including amino acids and peptides.ResultsThe present work describes an efficient one step green synthesis of 4-arylidene-2-phenyl-5(4H)-oxazolones (azlactones) via the multi-component synthesis by the mechanochemical grinding of glycine, benzoyl chloride, an aromatic aldehyde and fused sodium acetate in the presence of drops of acetic anhydride. This process is green, simple to handle, step and atom efficient, economical and environmentally friendly, because it does not require a reaction solvent or heating, we introduced the yield economy [YE] as a metric to assess the conversion efficiency of grinding and conventional synthetic reactions of azlactones. The structures of the newly synthesized compounds were elucidated by elemental and spectral analyses.ConclusionIn conclusion, we have developed a simple, efficient and eco-friendly strategy for facile synthesis of azlactones. The key advantages of this strategy, over conventional approach, include its simple, solvent free conditions, as well as its facile work-up, high yield economy and environmental friendliness. It is also successful in achieving three of the green chemistry objectives of a solvent free operation, high atom economy and step efficient. Thus, combining the features of both economic and environmental advantages.Graphical abstractAn efficient one step green synthesis of azlactones via multicomponent synthesis by a mechanochemical grinding.

Synthesis of some new phthalazines and their evaluation as corrosion inhibitors of steel

A convenient synthesis has been achieved of 11 substituted phthalazines starting from the condensation of 2-(p-toluoyl)benzoic acid with hydrazine and some of its simple congeners, H2NNHR. Four of the phthalazines showed activity as inhibitors of the corrosion of steel immersed in 5 M HCl solutions.