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A novel and efficient route was established for the synthesis of a series of ( Z )-5-(2-(heteroaryl-2-yl) and ( Z )-5-(3-(heteroaryl-3-yl)-1-(phenyl)vinyl)-1 H -tetrazoles ( 3a – g and 6a – f , respectively) from cyanostilbene analogs containing benzo[ b ]thiophene, benzo[ b ]furan, and indole moieties utilizing tributyltin azide as a Lewis acid. This 1,3-dipolar [3+2]cycloaddition of azide to the cyano group of the cyanostilbene precursor molecule affords good yields of the corresponding tetrazolylstilbene analog and constitutes a simple and cost-effective procedure.

(-)-Lobeline (1) (2R, 6S, 10S-, Fig. 1) is the major alkaloidal constituent of Lobelia inflata, a plant native to North America with a long history of use as a natural remedy. The plant is also cal...

All seventeen new compounds (structure examples (IV)) possess promising activity against the screened bacterial strains.

Use of a novel reagent has been established for the synthesis of a series of 4,5-diaryl-2H-1,2,3-triazoles (6a-i and 9a-e) from cyanostilbene analogs of benzo[b]thiophene, benzo[b]furan and indole, catalyzed by L-proline via Lewis base-catalyzed one-step [3+2]cycloaddition of azide. This method provides an efficient, simple and environmentally benign procedure that affords good yields and relatively short reaction times.

2H-1,2,3-Triazoles (2) were synthesized by [3+2] cycloaddition of (Z)-2,3-diaryl substituted acrylonitriles (1) with sodium azide and ammonium chloride in DMF/water. This method represents a facile and efficient reaction procedure for the synthesis of 4,5-diaryl-2H-1,2,3-triazoles in modest to good yields.

Sodium fluoride was found to be a simple, mild and efficient catalyst for the synthesis of 2,4-disubstituted 1,3-thiazoles and selenazoles utilizing phenacyl bromides/3-(2-bromoacetyl)-2H-chromen-2-one and thiourea/phenylthiourea/selenourea in aqueous methanol at ambient temperature. Analytically pure products are formed within 1–3 min in excellent yields.

Two facile procedures for the cyclocondensation of substrate (I) with the building blocks (II) or (IV) to produce fused thiazolopyrimidinone derivatives are developed.

An efficient synthesis of cis-2,6-di-(2-quinolylpiperidine) has been developed. The key steps involve Wittig reaction of N-Cbz-protected cis-piperidine-2,6-dicarboxaldehyde (3) with 2-(triphenylphosphinyl-methyl)quinoline bromide (4) and sequential removal of the N-Cbz group and double bond reduction. This synthetic procedure provides an efficient preparation for this useful norlobelane analogue.

A simple, mild, and highly efficient protocol for the synthesis of fused 2-oxo-4-aryl-2H-chromene-3-carbonitriles has been developed starting from fused 2-amino-4-aryl-4H-chromene-3-carbonitriles utilizing Vilsmeier conditions.

A series of azaaromatic quaternary ammonium analogues, e.g. (I) and (II), is discovered as potent and selective α9α10 nicotinic acetylcholine receptor (nAChR) antagonists.

An efficient method for the synthesis of 2-substituted benzimidazoles has been developed. In this method, benzo[c][1,2,5]thiadiazole-4,5-diamine was condensed with different aldehydes in the presence of cellulose sulfuric acid under solvent-free conditions by simple physical grinding of reactants using a mortar and pestle at room temperature. The methodology is mild, high-yielding, and green, and the catalyst could be easily recycled.

A series of 3-[benzimidazo(1,2-c)quinazolin-5-yl]-2H-chromene-2-one (6a–6f) and 3-[benzothiadiazole- imidazo(1,2-c)quinazolin-5-yl]-2H-chromene-2-one derivatives (7a–7f) that incorporate a variety of substituents at the 6- and/or 8-positions of the coumarin moieties have been synthesized utilizing cellulose sulfuric acid as an efficient catalyst under both conventional heating and microwave irradiation procedures. These analogs were evaluated for their antimicrobial activity against Bacillus subtilis, Staphylococcus aureus, Streptococcus pyogenes (Gram-positive bacteria), Escherichia Coli, Klebsiella pneumonia, Salmonella typhimurium (Gram-negative bacteria), and Aspergillus niger, Candida albicans, and Aspergillus flavus (Fungi). Two analogs, 6c (a 6,8-dichloro analog, MIC[SA] = 2.5 μg/mL; MIC[ST] = 2.5 μg/mL) and 7d (a 6,8-dibromo analog, MIC[ST] = 2.5 μg/mL) were identified as potent antibacterial agents, and two analogs, 6b (a 6-bromo analog, MIC[AF] = 10 μg/mL) and 6d (a 6,8-dibromo analog, MIC[AF] = 15 μg/mL; MIC[CA] = 15 μg/mL), were identified as potent antifungal agents. Based on the MIC data, analogs 6b, 6c, 6d, and 7d were identified as the most potent antimicrobial agents in the series.

The reaction is conducted under solvent-free conditions and can also be carried out without microwave irradiation but with prolonged reaction time.

Newly synthesized title compounds (III) are evaluated for in vitro cytotoxicity against a panel of 57 human tumor cell lines.

The analogues (IV) of lobelane are synthesized by replacing its phenyl groups with either pyridyl, indolyl, or quinolyl groups.

A convenient, scalable, and commercially viable process for the production of the antidepressant drug bupropion hydrochloride (III) is reported.

The conformations of 3′-azido-terminated-sulfonate-dimer 1 and 3′-amino-terminated-sulfonamide-dimer 2 are characterized by the following features: (1) The 5′-terminal nucleoside moiety of 1 has a S-type sugar (87% S), a staggered γ+ (rotamer across the C4′C5′ bond (65%) and an anti orientation of the base about the glycosidic bond. The 5′-terminal nucleoside moiety of 2 has an almost equal population of S and N conformations, a staggered γ+ rotamer (69 %) and an anti orientation of the base. (2) The 3′-terminal nucleoside moieties of 1 and 2 are in ∼50% N ⇄ S equilibrium and the γt conformer is the most populated. A comparison of the conformational properties of 1 and 2 with the natural thymidyl(3′ → 5′)thymidine [d(TpT)] 3, thymidylyl-(3′ → 5′)-5′-thio-5′-deoxythymide d(TpST)5 4 and thymidinylacetamido-[3′(O)→5′(C)]-5′-deoxythymidine NH2d(TcmT)5 5, show the following characteristics: (i) The conformational preference of the sugar ring is partially determined by the gauche effect. This means that the more polar the C3′X bond due to the electronegative character of the 3′-α-X substituent, the more than N ⇌ S equilibrium is biased toward the S-type conformation: 3′-O-S > 3′-O-H > 3′-N3 > 3′-NH2. (ii) The conformation about the C4′C5′ bond (γ) is also influenced by the gauche effect based on the nature of the 5′-substituent and by the ability of the 5′-substituent to form hydrogen bonding with the H6 of thymine. Thus, the population of the γ+ conformer follows the order: 5′-O > 5′-N > 5′-S > 5′-C. (iii) The C5′C6′ bond has a slight preference for the βt conformation (56 % βt in 1 and 58 % βt in 2), while in natural d(TpT) 3, the C5′O5′ bond accounts for 83% of βt conformation. Upon substitution of the 5′-oxygen by 5′-sulfur, as in d(TpST) 4, the population of βt conformer was found to decrease to 57 %. This decrease in the βt population in 1, 2 and 4 is a result of the reduced polarity of the 5′CX [X = CH2 in 1 and 2 and X  S in 4] in comparaison to the 5′CO bond in 3, which weaken the gauche effect.

An improved method for the synthesis of 2-cyanomethyl-1-methylpiperidine is reported.

N-benzoyl amino acids 1a–g react with excess oxalyl chloride at room temperature followed by addition of alcohols to afford 4-substituted 2-phenyloxazole-5-carboxylates 3a–g.

A new route to synthon (V) is presented which overcomes the difficulties of known procedures.

The synthesis of several novel substituted (Z)-2-amino-5-(1-benzyl-1H-indol-3-yl)methylene-1-methyl-1H-imidazol-4(5H)-ones structurally related to aplysinopsin have been carried out under microwave irradiation and conventional heating methods. The analogs 3a, 3b, 3d-3g,3k and 3l were evaluated for their in vitro cytotoxic activity against an NCI 60 human tumor cell line panel. Compound 3f exhibited good growth inhibitory properties against all but four of the human cancer cell lines examined, and afforded LC(50) values

Preparation of L-indospicine in eight steps by a reaction sequence starting with L-lysine.

Biosupported cellulose sulfuric acid has been found to be an efficient solid acid catalyst for the one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones. The advantages of this method are avoidance of harsh reaction conditions, ecofriendly chemistry, operational simplicity, high yield, and reusable catalyst.

1,3,4-Oxadiazoles and their derivatives have a wide range of biological and therapeutic properties such as antimicrobial [1], antifungal [2], and anti-inflammatory action [3]. Also, vinblastine-like [4] oxadiazole molecules that incorporate a coumarin moiety have been reported as potent antitumor and antibacterial agents [5,6]. Because of these important findings, the synthesis of these kinds of molecules has attracted significant interest. The general synthesis of oxadiazoles can be classified into four main synthetic strategies as follows: (i) cyclization of diacylhydrazines [7–11], (ii) oxidation of acyl hydrazones [12,13], (iii) acid-catalyzed condensation of acyl hydrazides with orthoesters [14–18], and (iv) solid-state synthesis and other methods [19–27]. However, these methods suffer from harsh reaction conditions and long reaction times. Therefore, it was deemed necessary to develop efficient and simple procedures for the synthesis of these biologically important oxadiazole derivatives.

N -Chlorosuccinimide has been identified as a convenient and safe alternative oxidant for the oxidative condensation of isothiocyanates and isocyanates to afford 1,2,4-thiadiazolidine-3,5-diones.

An efficient and convenient method is described for the synthesis of 1,8-naphthyridines in excellent yields by condensation of 2-aminonicotinaldehyde with various active methylene compounds in the presence of sulfamic acid as the catalyst in a solvent-free media using both conventional heating and microwave irradiation.

CuPy2Cl2 is an efficient catalyst for the preparation of propargylamines via three-component coupling reaction of aromatic aldehydes, amines, and aromatic alkynes stirred at 95 °C without using any solvent to afford the corresponding products in good yields. The reaction mixture was irradiated at 450 W in a microwave oven to furnish the expected products in excellent yields.

An efficient and convenient method for the synthesis of substituted coumarins via Pechmann condensation of different phenols with ethylacetoacetate in the presence of ammonium cerium(IV) nitrate as the catalyst in a solvent- free media using both conventional heating and microwave irradiation.

Dipyridine cobalt chloride is a novel catalyst for the Pechmann condensation involving different phenols and ethylacetoacetate under solvent-free conditions using both conventional methods and microwave irradiation. It gives the corresponding coumarins in excellent yields with high purity. The catalyst is thermally stable, inexpensive and recyclable. A faster reaction and higher yields compared to the conventional method and no side products were identified using microwave irradiation. In this reaction, electron releasing groups on the phenol ring shown more reactivity and gave high yields than simple phenol. These products were identified by 1 H NMR, 13 C NMR, MS, IR and elemental analysis.

β-Nicotyrine, a minor tobacco alkaloid, can be rapidly prepared in good yield from the dehydrogenation of S-(-)-nicotine over MnO2 with microwave irradiation. This method is superior to dehydrogenation reactions that utilize S-(-)-nicotine and MnO2 in a variety of solvents under reflux.

A seven step synthesis of the conformationally restricted phenylalanine analogue 9 from cycloheptadiene (1) is described.

As part of a drug discovery program using high-throughput radioligand-binding assays, aminoanthraquinones were identified as potential modulators of N-methyl-D-aspartate (NMDA) receptor function. Aminoanthraquinones may represent a novel class of polyamine binding site ligands with a unique pharmacophore and may facilitate the rational design of novel NMDA-receptor modulators.

A series of 5-benzoyl-5-phenyl- and S-phenyl-5-phenylhydroxymethylhydantoins have been synthesized from the reaction of urea, N-monosubstituted ureas and sym-N-N-disubstituted ureas with phenyltriketone hydrate, via a pinacol-pinacolone-type rearrangement mechanism. The compounds were evaluated for anti-convulsant activity in mice.

A series of 6-hydroxy endo- and exo-derivatives of 2-aminobenzonorbornene has been synthesized and evaluated for antinociceptive activity in the mouse. The results indicated a stereospecific effect in the antinociceptive responses exhibited by the two isomeric groups of compounds. The exo-amines 10a-10c were inactive in both the tail immersion and tail clip tests. The corresponding endo-isomers exhibited antinociceptive properties; 4a was the most active compound tested but was toxic at the dose administered.