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This review highlights the methods used for the synthesis of phthalazine derivatives and fused phthalazinones. Their reactivity and synthetic importance were investigated. Phthalazine derivatives can be used as building blocks for heterocycles as well as fused heterocyclic compounds.

A series of novel isoquinoline derivatives are synthesized by reaction of the title isochromenedione (I) with hydrazides, amines, diamines, and 2-aminothiophenol.

Novel 2,5-disubstituted thiadiazoles bearing different substituents are obtained by cyclization of thiosemicarbazide (IV) followed by reaction with electrophilic reagents, such as aromatic aldehydes, isatin, phenyl isothiocyanate, and carbon disulfide.

In this work, tetra butyl ammonium hydroxide ([Bu4N]OH) and magnetic nano particles (Fe3O4@SiO2@(CH2)3NH2) were introduced as efficient catalysts for the regioselective ring opening of epoxides including aromatic and aliphatic of epoxides to give the corresponding β-phthalimido-alcohols under mild conditions. A various range of β-phthalimido-alcohols as new compounds were prepared and fully characterized by IR, 1H as well as 13C NMR and mass spectra. Also the synthesized compounds were studied for antioxidant properties by DPPH free radical scavenging assay. The results indicated that studied β-phthalimido-alcohols derivatives have effective antioxidant functions (IC50: 0.142–0.356 mg mL−1) in compare with BHT (IC50: 0.122 mg mL−1) and ascorbic acid (IC50: 0.146 mg mL−1) as standards. This may be a new health-care food and drug supplement for special use in the future.

Zika virus is an emerging virus that has been defined by the World Health Organization as a serious global biological-threat. Zika virus is an arbovirus from the flavivirus genus that is linked to microcephaly after prenatal transmission from the infected mother and most recently Guillain–Barre Syndrome. The need for innovative research methods is urgent due to the ambiguity surrounding Zika virus. The lack of experimental data regarding potential drug targets, strategies for design and drug resistance has prompted us to provide a comprehensive framework with structured theoretical and technical guidelines on potential drug targets, modeling and design of inhibitors against the virus, thus assisting and encouraging scientists from different research domains to fill the gap in this research area. We have also presented a 3D homology model of the ideal Zika viral target, the non-structural protein 5, identified the active binding sites of each domain of the protein and found potential compounds that may act as inhibitors. This report will be immensely beneficial toward the design of Zika virus drug inhibitors.

In this study, manganese (Mn) doped Calcium Tetraborate (CaB4O7) samples were prepared by the wet chemical method. Under beta irradiated, CaB4O7:Mn showed thermally stimulated luminescence (TSL) glow peaks at approximately 85 °C and 220 °C with a heating rate of 5 °C/s. Peak shape (PS) and various heating rates (VHR) methods were applied for determining the trap parameters such as order of kinetic (b), activation energy (E) and frequency factor (s). The results indicate that the main dosimetric peak of CaB4O7:Mn follows the second-order kinetic model. The thermal fading ratio of the material is around 15% at the end of one month period of storage. The results of the TL studies carried out on the CaB4O7:Mn dosimeter revealed that it has high sensitivity, which makes it very valuable in various dosimetric applications like space, medical, personal dosimetry and dating. Radioluminescence (RL) of CaB4O7:Mn was also studied. It is shown that the RL spectrum contains a wide band centered at 530 nm assigned to Mn2+ ion emission. A broad band emission feature peaked at 350 nm assigned to the non-bridging oxygen hole center (NBOHC) is also discussed and a model is proposed to explain this broad band feature.

FeNCN can be efficiently used as negative electrode material for alkali metal ion batteries.

Copper or silver salts promote a domino addition–cyclization reaction between terminal alkynes, carbon disulfide, and oxiranes in a regioselective manner to afford 1,4-oxathiane derivatives in good yield.

The novel cobalt—chitosan compound is used as a magnetic heterogeneous catalyst for the aerobic oxidation of alkyl arenes and alcohols.

Structural modifications of natural products with complex structures like steroids require great synthetic effort. A review of literature is presented on the chemistry of the steroidal hormone 17α-methyltestosterone that is approved by Food and Drug Administration (FDA) in the United States as an androgen for estrogen-androgen hormone replacement therapy treatment. The analog also offers special possibilities for the prevention/treatment of hormone-sensitive cancers. The testosterone skeleton has important functionalities in the molecule that can act as a carbonyl component, an active methylene compound, α,β-unsaturated enone and tertiary hydroxyl group in various chemical reactions to access stereoisomeric steroidal compounds with potent activity. In addition, microbiological methods of synthesis and transformation of this hormone are presented.

Efficient N-arylation of N-heterocycles and amines with aryl halides is achieved using a novel nanopolystyrene-anchored Cu(II) tetrazole complex as stable heterogeneous catalyst.

Novel thiazolo [3,2-a]pyridine and thiazolo[3,2-a]pyrimidine derivatives, pyrazolo[3,4-b]pyrano[2,3-d]thiazole, and coumarin derivatives were synthesized from readily obtainable starting materials such as (Z)-2-ethoxycarbonyl methyl-5-(4-chlorobenzylidene)-2-thiazolidin-4(H)one 3 and (Z)-4-(4-hydroxybenzylidene)-2-imino-2-thiazolidin-4(H)one 11.

A novel three-component reaction involving 2-methylbenzothiazole or 2,5-dimethylbenzothiazole, acetylenic esters and 1,3-dicarbonyl compounds such as (1,3-dimethylbarbituric acid or 1,3-indanedione) leading to the synthesis of spiro pyrrolobenzothiazole derivatives. The reactions proceeded smoothly at room temperature without using any catalyst. This method is very useful to functionalize benzothiazole derivatives in a one-pot operation. The structures of the synthesized compounds have been characterized by spectral studies.

The synthesis of palladium nanoparticles (Pd NPs) using an aqueous extract of leaves of Euphorbia thymifolia L. and their application in the ligand-free Stille and Hiyama cross-coupling reactions are reported here. Pd NPs were characterized using powder XRD, TEM, FT-IR and UV-vis techniques. The synthesized Pd NPs exhibited excellent catalytic activity and the reactions generated the corresponding products in good to excellent yields. These methods have some advantages, such as efficiency, generality, high yield, elimination of ligand, organic solvent and homogeneous catalysts, cleaner reaction profiles, ease of product isolation and simplicity. The reactions were carried out in a green solvent i.e. water. The catalyst was quantitatively recovered and reused without significant loss in the catalytic activity.

A series of thiazoles (III) and (V), 1,3-thiazines (IX), and thiazolidine (VII) is prepared in the presence of an environmentally friendly basic chitosan-grafted-poly(vinylpyridine) catalyst.

Carbon-supported bimetallic CuPd nanoparticles are shown to be an efficient catalyst for the reduction of nitrorarenes and for the phosphine-free Suzuki—Miyaura coupling reaction.

Et3N-mediated reaction of perimidine ketene aminal (I) with hydrazonoyl chlorides (II) and (IV) affords regioselectively pyrazolyl-perimidines (III) or pyrroloperimidines (V), respectively.

Copper nanoparticles supported on carbon appears to be an excellent heterogenous catalyst for the cyanation of aryl iodide as well as the synthesis of triazoles via “click” reactions under ligand-free conditions.The catalyst can be recycled and reused up to five runs without significant loss of catalytic activity.

Ligand-free Heck coupling reactions of styrenes and alkyl acrylates with aryl bromides and iodides provide the corresponding products in high yields.

A one-pot three-component reaction of various N-heterocycles with acetylenic esters and cyclic secondary amines is developed.

An efficient and versatile synthesis of indane, tetralin and benzosuberan derivatives has been developed; the synthesis starts from nonactivated aromatic compounds bearing unsaturated side chains and is a bismuth(III) or indium(III) trifluoromethanesulfonate-catalysed atom-economic process. A variety of polycyclic compounds have been isolated in high yields. Lactonisation could be observed for esters with 2,2-disubstituted terminal olefins through a Lewis acid catalysed reaction between the olefin and one of the ester groups.

A series of new pyrimidinone derivatives is synthesized starting from oxiranyl aryl ketone (I).

A variety of new 2,3-disubstituted quinazolinone derivatives is synthesized using hydrazide (IV) as key intermediate.

The synthesis of a variety of phthalazine derivatives bearing an other heterocyclic ring starting from phthalazine hydrazide (I) is described.

Dimethyl homophthalate condensed with isatin to give the unexpected five membered lactone 3 rather than the half ester 1 and the δ-lactone2. Treatment of compound 3 with excess hydrazine hydrate afforded phthalazinone carbohydrazide 4 which represents a novel method for the synthesis of phthalazinone derivatives. The carbohydrazide 4 upon treatment with carbon disulphide afforded 1,3,4-oxadiazole derivative 5, which reacted with ethylchloroacetate to give the S-alkylated product 6. The structure of compound 3 compared with 2 was discussed using hyperchem professional (7) AM1 calculations, X-ray single crystal structure and complete spectral data.

Benzoxazinone (I) reacts with different nitrogen nucleophiles leading to various quinazoline and quinazolinone derivatives.

The synthesis of a new, conformationally restrained analog of tryptophan, 1,2,3,4-tetrahydro-2-amino-2-carboxy-cyclopent[b]indole (5) is described. The key step involves the BF3· Et2O Catalyzed intramolecular cyclization of α-diazoketone 2b into the 1,2,3,4- tetrahydro-cyclopent[b]indol-2-one (3).

The reaction of 2-[p-(N,N'-dimethylaminophenyl)]- naphtho [2,1-b] - 2,3 - dihydropyran -4- one 1 with 2- mercaptoaniline 2 has been investigated. The yet unreported 6-(p-N,N'-dimethylaminophenyl)-naphtho [2,1-b]- pyrano- [3,4-b] benzo- (4H) -1,4-thiazine 3 system has been synthesised and characterised on the basis of spectral and analytical data. A novel synthestic route to naphtho (2,1-b)-pyrano (4,3-c) pyridazin-3-one 6 is reported.

The reactions of (VII), easily prepared starting from diester (I), with various N-nucleophiles is studied.

The starting materials, 2-amino-3-cyano-4-(3,4,5-trimethoxyphenyl)-4H-pyran0[3,2-hlquinoline 1 and ethyl-2-amino-4-(3,4,5-trimethoxyphenyl)-4H-pyrano [3,2-hlquinolin-3-carboxylate 2 were synthesised from 8-hydroxyquinoline and a-cyano-3,4,5-trimethoxycinnamonitrileand/or ethyl-a-cyano-3,4,5-trimethoxy-cinnamatre respectively. In order to construct a third heterocyclic ring 1 and 2were condensed with ethyl bromoacetate, formarnide, carbon disulfide to afford pyrrolo-, pyrimido- and thiazinopyranoquinolines 3-6respectively. The S-alkylated products 7 and 8 were obtained by the effect of chloroacetonitrile and/or ethyl chloroacetate on thiazinopyranoquinoline derivative 6. The attempt of cyanomethylation of the amino functional group of 1 to yield 10 with chloroacetonitrile in AcOHIAcONa failed and instead, pyridopyranoquinoline derivative 9 was obtained which is visualized to occur via cyclization of the initially formed acetylarnino derivative by nucleophilic attack on the cyano group. Acetylation of 1 and 2 with acetic anhydride afforded the mono- and di-acetyl derivatives 11a and 11b respectively. A plausible explanation to form the mono-derivative with 1 and the di-derivative with 2 is the higher deactivating effect of the cyano function over that of the carboxyethyl group. Furoylation of 1 and 2 was achieved by furoyl chloride to give 12a and 12b respectively. The structural features of pyranoquinoline 2 were inferred from its microanalysis and spectral data such as IR,1H-NMR and MS as well as its chemical reactions, as a bifunctional compound with carbon nucleophiles namely, phenyl isothiocyanate and nitrogen nucleophilic species namely, p-toluidine, benzylamine, aniline and hydrazine hydrate to give pyrimidopyranoquinoline derivative 13, carboxamides 14a-c and carboxyhydrazide 15 respectively. When the hydrazide 15 was treated with carbon disulfide inpresence of KOH, it afforded the potassium salt 16 which was submitted to react with hydrazine hydrate at room temperature to give 17. The hydrazido group of 15was utilized to construct heterocyclic moieties attached to postion-3 of the pyranoquinoline structure. Thus, the reaction of the carboxyhydrazide15 with phenyl isothiocyanate, acetylacetone, and benzoylacetone resulted in the formation of 18, 19a and 19b respectively. Ethyl carbazate as a typical mesophile reacted with 2 to afford a fused tetracyclic product triazepinopyranoquinoline 20 via cyclization of the initially formed hydrazide. Among sixteen compounds screened against E. coli and S. aureus respectively,compounds 2 and 14c show a high order of antibacterial activity against both bacteria. 12b is strongly potent against Staphylococcus aureus.

5-Amino-3-anilino-1H-pyrazole-4-carbonitrile 1 was alkylated with various halo reagents under phase transfer conditions to give the corresponding imidazopyrazole derivatives 2a, 2b, 2c, 3, 4, 5, 6. Pyrazolo[1,5-a] pyrimidine derivatives 11, 12, 13, 14 were prepared by treating compound 1 with different dicarbonyl reagents, namely, diethymalonate, ethyl 3-oxo-3-phenylpropanoate, pentane-2,4-dione or ethyl 3-oxobutanoate.

Reaction of dicyandiamide with series of amino acids afforded guanidinyl pyrazolones , respectively. Although reaction of dicyandiamide with urea, acetamide, bezamide, allantion, p-aminobenzoic acid, sulphanilic acid, and adenine gave biguanides , respectively. All compounds have been characterized on the basis of IR and 1H-NMR.

The transformation of aryl iodides instead of aryl bromides requires slightly shorter reaction times and affords the corresponding products in virtually identical yields.

Supported TfOH appears to be a useful and recyclable heterogeneous catalyst for the rapid and efficient synthesis of guinoxaline derivatives via condensation of aromatic 1,2-diamines with 1,2-dicarbonyl compounds in water.

TiO2 nanoparticles are an efficient, easily recoverable, and reusable heterogeneous catalyst for the synthesis of N-arylureas (II) by hydration of cyanamides (I) using formic acid.

This review deals with the preparation of new derivatives of pyrimidine-1-acetic acid hydrazide containing an azetidinone moiety was shown in the synthesis of 3-chloro-1-(4- pyrimidine methylcarbonylamino)-4-phenyl-azetidin-2-one (11a-h)and their biological activity by the reaction of a mixture of pyrimidine -1-acetic acid hydrazide (10a-h). A series of novel β - lactams derivatives were designed and synthesized by reacting functionalized acylhydrazones with 2-chloroacetyl chloride 25 . The general method for the preparation of β -lactams derivatives containing natural Gallic acid moiety 15a-h are outlined in (Scheme2 ). The pharmacological importance of β-lactams and their utility as building blocks in organic synthesis have directed considerable research activity toward the synthesis of suitably substituted 2-azetidinone rings.