Microwave-Assisted One-Pot Synthesis of 3-Amino-1-aryl-8-bromo-2,4-dicyano-9H-fluorenes in Water

A series of novel 3-amino-1-aryl-8-bromo -2,4-dicyano-9H-fluorenes derivatives were prepared using arylaldehyde, 4-bromo-indanone, malononitrile, and sodium hydroxide as the reactants in water via one-pot synthesis under microwave irradiation. A green and efficient method was successfully developed via microwave irradiation. The method possesses several advantages, such as environmental friendliness, shorter reaction time, and simple workup procedure.      

Convenient Synthesis of Sorafenib and Its Derivatives

This article describes a convenient synthesis of sorafinib and its derivatives from phenyl carbamates in good yields. This procedure, avoiding toxic phosgene, is especially suitable for large-scale preparation.      

Novel and Efficient Synthesis of tert-Butyl-2-(4-(2-aminoethyl)phenylthio)-2-methylpropanoate,a Key Intermediate in the Synthesis of Ureido Thioisobutyric Acid

A convenient and cost-effective synthesis of pharmacologically important tert-butyl-2-(4-2-aminoethyl)phenylthio)-2-methylpropanoate from commercially available 2-2-phenyl-1-ethanol is described.     

Convenient Synthesis of 5-Alkylfuran-2(5H)-ones

A convenient synthesis of 5-alkylfuran-2(5H)-ones are described starting from 3-nitropropanoate and aldehydes, promoted by neutral alumina, in 35–60% overall yields, via a condensation–lactonization–elimination pathway.      

Synthesis of the Precursor of K252a and Its Analogs

A practical and efficient asymmetric synthesis of the key precursor furanose 3 for the synthesis of K252a and CEP-701 has been achieved in nine steps with an overall yield of 12.8% from (R)-methyl β-hydroxytetradecanoate 5, an industrial intermediate for production of orlistat.      

KAl(SO4)2 · 12H2O as a Recyclable Lewis Acid Catalyst for Synthesis of Spirooxindoles in Aqueous Media

A simple and efficient procedure for the synthesis of spirooxindole has been described that employs a three-component condensation reaction in one pot using isatin, active methylene reagent, and 1,3-dicarbonyl compounds in an aqueous medium.     

Biginelli-Like Cyclocondensation Reaction: Efficient Synthesis of 4,6-Diarylpyrimidin-2(1H)-one Under Solvent-Free Conditions

An efficient and facile synthesis of 4,6-diarylpyrimidin-2(1H)-one via a Biginelli-like reaction of aromatic aldehydes, aromatic ketones, and urea in the presence of NaOH under solvent-free conditions using a heating method has been developed. Compared with the classical reaction conditions, this new synthetic method has the advantages of excellent yields, shorter reaction time, and mild reaction conditions.      

Copper(I)-Catalyzed Tandem Cyclization/Condensation Reaction to Novel 4,5-Dihydropyrazolo[1,5-a]quinolines and Pyrazolo[1,5-a]indoles

A facile copper(I)-catalyzed tandem reaction for the synthesis of 4,5-dihydropyrazolo[1,5-a]quinolines and pyrazolo[1,5-a]indoles is reported here. High efficiency and good yields are displayed in this transformation under mild reaction conditions.      

Stannous Chloride–Promoted Synthesis of S-Allyl-N-aryl Dithiocarbamates under Solvent-Free Conditions

Abstract

A highly efficient method of synthesis of S-allyl-N-aryl dithiocarbamates using SnCl₂ as a catalyst under solvent-free conditions is described. The mild reaction conditions, high yields, and shorter reaction period illustrate the good synthetic utility of this method.     

Effective Synthesis of 1,5-Disubstituted 2,1-Benzisothiazol-3(1H)-ones

A convenient and effective synthesis of novel 1,5-disubstituted 2,1-benzisothiazol-3(1H)-one derivatives is described. The approach involves nitration of inexpensive isatoic anhydride followed by its conversion to 5-nitro-2,1-benzisothiazol-3(1H)-ones in excellent yield and alkylation at the 1-position. The 5-amino group was further derivatized.      

The Reaction of (Phenyldimethylsilyl)dichloromethyllithium with Organoboranes. A Synthesis of α-Hydroxyorganosilanes and Ketones

The α-transfer reaction of organoboranes has been utilized to great advantage in the employment of organoboranes in synthesis.² We report here that this process can be used as illustrated in eq 1 to generate α-hydroxyorganosilanes, which can be converted to ketones. This procedure serves to incorporate two of the groups of the organoborane into the product as well as generating the hydroxyl group via oxidation of the newly formed carbon-boron bond.     

Highly Stereoselective Synthesis of β-Amino Ketones via a Mannich Reaction Catalyzed by Cellulose Sulfuric Acid as a Biodegradable,Efficient, and Recyclable Heterogeneous Catalyst

The efficient use of cellulose sulfuric acid as a heterogeneous catalyst promotes three-component, one-pot Mannich reaction of various ketones, aromatic aldehydes, and aromatic amines in ethanol to make the corresponding β-amino ketones with high stereoselectivity in favor of the anti-isomer. This protocol has several advantages such as good yield, mild reaction conditions, no environmental hazards, and simple workup procedure.      

Synthesis of meso-TPP Revisited: Its “Green-Oriented” Optimization Under Controlled Microwave Heating

A practical and proecological improvement for synthesis of meso-tetraphenylporphyrin (meso-TPP) under microwave irradiation is described. A cyclocondensation reaction of benzaldehyde and pyrrole followed by oxidation of the porphyrinogen formed as an intermediate in a small amount of propionic acid at 120 °C (under controlled microwave heating) resulted in conversion to meso-TPP in a reasonable yield (ca. 30%) in preparative-scale experiments (300–500 mg). The influence of many parameters such as the concentration of reagents, catalyst, solvent, temperature, reaction time, and oxidant on the reaction yield was studied. The environmental motive in this improvement is reduction of solvent volume (ca. 250 times). Also, some toxic reagents were eliminated from the procedure.      

Microwave Irradiation for Accelerating Synthesis of 5,6-Diphenylimidazo[1,2-a]pyrimidines Based on Isoflavones

Microwave irradiation was used to accelerate the cyclocondensation of isoflavones with 2-aminoimidazole to synthesize 5,6-diphenylimidazo[1,2-a]pyrimidines. A series of 17 new compounds were characterized by Fourier transform infrared, NMR, and elemental analysis. 5-(2-Hydroxyl-4-isopropoxyphenyl)-6-phenylimidazo-[1,2-a]pyrimidine was determined by x-ray diffraction. A variety of substrates can participate in the process with good yields and purities, making this methodology suitable for library synthesis in drug discovery.      

Hydrosilylation of Ketones Catalyzed with Mg-Al-O-t-Bu Hydrotalcite

In this article, a simple and efficient procedure of hydrosilylation of ketones catalyzed with Mg-Al-O-t-Bu hydrotalcite was described. Hydrosilylation of ketones with triethoxysilane was carried out smoothly at room temperature in the presence of Mg-Al-O-t-Bu hydrotalcite without solvent, and the conversions of ketones were more than 90%. The recyclability of Mg-Al-O-t-Bu hydrotalcite was also tested.      

The Nitro Ketal Approach to Furane Systems. Total Synthesis of Racehic Bilobanone

Continuing our studies with the chemistry of ketals of β-nitro ketones¹, we wish to describe a new furane synthesis exemplified by a total synthesis of the sesquiterpene bilobanone 1 ².     

Disodium Hydrogen Phosphate as an Efficient and Cheap Catalyst for the Synthesis of 2-Aminochromenes

An efficient and convenient method for the synthesis of 2-aminochromene by the one-pot, three-component reaction of an aromatic aldehyde, malononitrile, and α- or β-naphthol in the presence of a catalytic amount of disodium hydrogen phosphate under solvent-free conditions is described.      

New Method for the Synthesis of Benzyl Alkyl Ethers Mediated by FeSO4

The synthesis of benzyl alkyl ethers from benzyl bromides and alcohols using FeSO₄ as a recoverable and reusable mediator has been described without use of base and cosolvent under mild conditions.