A facile two-step synthesis of 8-arylated guanosine mono- and triphosphates (8-aryl GXPs)

We report a simple and high-yielding two-step procedure for the preparation of 8-arylated guanosine mono- and triphosphates (8-aryl GXPs). The key step of our synthesis is the Suzuki-Miyaura coupling of unprotected 8-bromo GMP and 8-bromo GTP with various arylboronic acids in aqueous solution. The 8-bromoguanosine 5'-phosphates required as cross-coupling substrates were prepared from 8-bromoguanosine via an optimised Yoshikawa procedure.     

DFT studies on global parameters,antioxidant mechanism and molecular docking of amlodipine besylate

Amlodipine besylate (AMB) is a synthetic dihydropyridine calcium channel blocker with antihypertensive and anti-anginal effects. Quantum computational investigations on AMB were done using DFT/B3LYP/6-311++G (d, p) level of theory, to study the molecular structural properties, nonlinear properties and antioxidant properties of AMB. The electrophilic and nucleophilic sites along with complete NBO analysis helps to locate the intermolecular electronic interactions and their stabilization energies. Complete NBO analysis was additionally done to locate the intermolecular electronic interactions and their stabilization energies. Charge distributions of Mulliken population, NBO and MEP are correlated. Also, the antioxidant properties of AMB were assessed to check whether these antioxidant effects contribute to the effects of antioxidant therapy. Further, the molecular docking studies of these compounds demonstrated a good selectivity profile with Monoamine oxidase B with better binding affinity and confirms AMB is a potent antioxidant.     

A facile synthesis of cyclotriveratrylene

Cyclotriveratrylene (CTV) can be readily synthesized by chloromethylation or bromomethylation of dimethoxybenzene with halomethyloctyl ether in the presence of SnCl₄. The reaction provides the trimer exclusively and in high yield. Recrystallizations from benzene or CHCl₃ yielded the solvent inclusion complexes and did not remove other inclusion impurities. Flash chromatography on silica yielded the pure CTV.¹³C NMR shows only five signals and no impurities.     

A facile synthesis of N-sulfinylaldimines

A simple and efficient procedure for the synthesis of N-sulfinylaldimines (sulfinimines) from sulfinamides and aldehydes is described. The reaction was carried out in the presence of t-BuOK or NaOH. The method is applicable for the synthesis of optically active sulfinimines.     

A facile synthesis of muscimol

The psychoactive isoxazole muscimol $\text{10}$ has been synthesized in three steps from propargyl chloride.     

A facile synthesis of cyclononatripyrroles

A facile synthesis of a functionalized cyclononatripyrrole derivative is described. It involves the iodine-catalyzed cyclotrimerization of ethyl 3,3-dimethyl-5,7-dihydro[1,3]dioxepino[5,6-c]pyrrole-6-carboxylate in methanol. The product obtained in this way exists solely in the crown conformation typical of cyclononatripyrroles. However, in contrast to previously reported compounds of this class, it possesses three labile methoxymethyl arms that can be further functionalized under acidic conditions.     

A facile synthesis of cyanophenothiazines

A one-pot synthesis of 1, 3 and 4-cyanophenothiazines and a two-step approach to 2-cyanoisomer have been developed. The condensation of 2-aminobenzenethiol and 2,3 or 3,4-dihalogenobenzonitriles followed by Smiles rearrangement or by intramolecular aromatic substitution gave the desired ring systmes.     

A facile synthesis of ulicyclamide

Ulicyclamide (1), a cytotoxic cyclic peptide from a marine tunicate, has been efficiently synthesized by the solid-phase method using diethyl phosphorocyanidate for the coupling and trimethylsilyl triflate for the final deprotection.     

A facile synthesis of polyfoluoroalkyl-lactonization

2(-Benzoxazolyl substituted cyclopropane derivatives were synthesized in the yield of 73-89% from the reaction of telluronium ylides with chalcones.     

Single configuration interaction study on conjugated betainic chromophores based on DFT optimized geometries

The structure of a series of heterocyclic betaines was calculated by methods of density functional theory (DFT). The charge distribution and bond characteristics of these compounds were analyzed by Weinhold’s natural bond orbital analysis (NBO) and by natural resonance theory (NRT). In order to probe the aromatic character of the ring fragments, Schleyer’s nucleus-independent chemical shifts (NICSs) were calculated by GIAO-RHF. Ab initio single configuration interaction calculations (SCI) correctly predict intense π→π* transitions at low energies, but the transition energies of the color bands are overestimated. Torsion around the interfragmental bond increases the charge separation between the molecular fragments and the dipole moment. The molecular fragments become increasingly aromatic. The absorption wavelengths increase on torsion while the oscillator strengths decrease.     

A facile synthesis of unsymmetrical ureas

A facile and versatile method for the synthesis of unsymmetrical ureas from readily available reagents is reported. In the first step trifluoroethylchloroformate is reacted with a stoichiometric amount of a primary amine to give an intermediate trifluoroethyl carbamate. The addition of a second amine (primary or secondary) to the trifluoroethyl carbamate furnishes corresponding unsymmetrical ureas in 75-85% yield. A simple workup procedure, the high yields obtained, and the purity of the isolated products are suitable for the parallel synthesis of combinatorial libraries of unsymmetrical ureas with high structural and functional diversity.     

A facile synthesis of fluorochlorobromoacetic acid

Fluorochlorobromoacetic acid was sythesized in the sequence of four steps from 1,1,2-trifluoro-2-chloroethylene in an overall yield of approximately 25%. 1,1,2-Trifluoro-2-chloroethylene was first allowed to react with sodium methoxide to form 1,2-difluoro-1-chloro-2-methoxyethylene, which was then brominated with elemental bromine and the reaction product treated with concentrated sulfuric acid to give methyl fluorochlorobromoacetate. This compound was hydrolized with a diluted sodium hydroxide solution to fluorochlorobromoacetic acid.This paper is dedicated to Professor Karl Schlögl on the occasion of his 65th birthday with warmest personal wishes     

A facile total synthesis of rutaecarpine

The indoloquinazoline alkaloid rutaecarpine has been synthesized efficiently by employing 9,10,11,12-tetrahydro-4H-pyrido[2,1-b]quinazoline-4,9-dione (4) as a key intermediate, which was prepared by adapting a Dieckmann condensation-decarboxylation sequence from quinazolinone diester 6.     

5-四氢呋喃基呋喃的合成

六碳醛糖与1,3-双桐或β-酮酸酯在氯化锌存在下缩合, 再经酸性条件下环化生成50-60%得率的5-四氢呋喃基呋喃类化合物。     

A facile synthesis of polysubstituted pyrroles

alpha-Aminoalkylcuprates prepared from CuX.2LiCl (X = Cl, CN) and 1 equiv of an alpha-lithiocarbamate undergo conjugate addition reactions to alpha,beta-alkynyl ketones in moderate to good yields, affording E:Z mixtures of alpha,beta-enones. Treatment of the conjugate adducts with PhOH/TMSCl in CH(2)Cl(2) effected carbamate deprotection and cyclization to afford a flexible two-step synthesis of substituted pyrroles.