Simple and Efficient Synthesis of 1,3-Dithioles with Pyrimidinylidene or Pyrazolylidene Substituents

Abstract

2-Pyrimidinylidene-1,3-dithioles or 2-pyrazolylidene-1,3-dithioles are prepared by a three-component condensation reaction of pyrimidine-tetraone or 1H-pyrazole-4,5-dione, carbon disulfide, and dialkyl acetylendicarboxylates in the presence of tributylphosphine.

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Phosphorylation of Acylated Trihydroxybenzene Derivatives by Phosphorous Triamides

Abstract

The phosphorylation of acylated trihydroxybenzene derivatives by amides of phosphorous acid was considered. The possibility of selective phosphorylation of triacetoxy phloroglucin was shown.

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Microwave-Assisted Direct Synthesis of 4H-1,2,4-Benzothiadiazine 1,1-Dioxide Derivatives

Abstract

We describe a rapid and convenient methodology for the preparation of diverse 3-aryl and 3-trifluoromethyl 4H-1,2,4-benzothiadiazine-1,1-dioxides in a one-pot microwave-promoted reaction between 2-aminobenzenesulfonamides and benzaldehydes, trifluoroacetic acid or benzoic acids.

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Regioselective Syntheses of 1-Aryl-substituted-5H-[1,3]thiazolo[3,2-a]quinazoline-5-ones During Sonogashira Coupling

Abstract

Reaction of 2-mercaptopropargylquinazoline-4-one with various aryliodides catalyzed by Pd–Cu leads to the regioselective formation of 1-arylsubstituted-5H-[1,3]thiazolo-[3,2-a]quinazoline-5-ones.

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A Simple Synthesis of Oxaphospholes

Abstract

Stable derivatives of oxaphospholes were obtained from the reaction between electron-deficient acetylenic compounds and phenacyl bromide or its derivatives in the presence of triphenylphosphine in acetonitrile as the solvent in excellent yields.

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Synthesis of an Enkephalin Analogue Containing an α,α-Disubstituted Heterocyclic Aminophosphonic Acid

Abstract

Synthesis of a phosphonopentapeptide enkephalin analogue was achieved from heterocyclic aminophosphonates via the coupling of Boc-Tyr-Gly-Gly-OH with phosphonodipeptide. The latter was formed by coupling Boc-Phe-OH with N-terminal α,α-disubstituted heterocyclic α-aminophosphonates.

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Melamine-Trisulfonic-Acid-Catalyzed Trimethylsilylation of Alcohols and Phenols

Abstract

A highly convenient method for the trimethylsilylation of alcohols and phenols via treatment by hexamethyldisilazane in the presence of melamine trisulfonic acid as a catalyst has been developed. A wide variety of hydroxyl groups were selectively protected under solvent-free conditions.

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Synthesis of Novel Thioethers from Polyhalobutadienes and Thiols

Abstract

Substituted perchlorobutadienes were synthesized from the reactions of hexachloro-1,3-butadiene with some thiols in ethanol in the presence of sodium hydroxide. The oxidation products were obtained from the reactions of thioethers with m-chloroperbenzoic acid. The structures of the new compounds were characterized by microanalysis and spectroscopic data.

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Poly[4-diacetoxyiodo] Styrene–Promoted Thiocyanation of Aromatic Ethers,Anilines, and Indoles

Abstract

Thiocyanation of aromatic ethers, anilines, and indoles have been achieved using ammonium thiocyanate in the presence of poly[4-diacetoxyiodo] styrene (PDAIS) in CH₃CN at room temperature.

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Efficient Organic Transformations Mediated by ZrOCl2·8H2O in Water

Abstract

Operationally simple and environmentally benign methods for some organic transformations comprising reductive coupling of sulfonyl chlorides, chemoselective deoxygenation of sulfoxides, and halogenation of alcohols mediated by ZrOCl₂·8H₂O/MX in water have been developed.

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An Efficient and Convenient Protocol for the Synthesis of Thiazolidin-4-Ones

Abstract

Without a catalyst and under solvent-free conditions, 2,3-disubstituted-1,3-thiazolidin-4-one 5a–j derivatives were synthesized efficiently via the three-component reaction of aryl hydrazide, aromatic aldehyde, and mercaptoacetic acid. All the newly synthesized compounds were confirmed by IR, ¹H NMR, and ¹³C NMR spectroscopy and elemental analysis.

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Succinimide-N-Sulfonic Acid: A Mild,Efficient, and Reusable Catalyst for the Chemoselective Trimethylsilylation of Alcohols and Phenols

Abstract

Succinimide-N-sulfonic acid (SuSA) is easily prepared by the reaction of succinimide with chlorosulfonic acid. This reagent is able to efficiently catalyze the chemoselective trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS). All reactions were performed under mild reaction conditions, giving excellent yields.

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A One-Pot Synthesis of Functionalized 2,3-Dihydrothiazoles from Isothiocyanates,Primary Alkylamines,and Phenacyl Bromides

Abstract

A simple, one-pot synthesis of N-(4-aryl-3-alkylthiazol-2(3H)-ylidene)anilines and N-(4-aryl-3-alkylthiazol-2(3H)-ylidene)benzamides via the reaction of primary alkylamines, α-bromoketones, and phenylisothiocyanate or benzoylisothiocyanate is described.

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Investigation on the Se-Acylation with N-Acylbenzotriazoles

Abstract

The acylation of Se-nucleophiles with N-acylbenzotriazoles was investigated. Samarium phenylselenolate and benzylselenolate (RSeSmI₂) reacted with N-aroyl and N-alkanoylbenzotriazoles smoothly and afforded the corresponding selenol esters in good yields. Treatment of the RSeSmI₂ with α,β-unsaturated N-acylbenzotriazoles afforded the anticipated α,β-unsaturated selenol esters in moderate yields, due mainly to the side reaction of conjugate addition.

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Phosphorylation of Dienyl Diprenoid Alcohols

Abstract

The reactions of geraniol, nerol, and linalool with N,N-diethylamido O,O-propylenephosphite and diethyl chlorophosphite were studied. On the basis of these studies, new dienyl diprenoid phosphite esters were obtained.

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A New and Efficient Procedure for the Production of 1,1-Diacetate from Corresponding Aldehydes Promoted by Silica Chromate (SiO2-O-CrO2-O-SiO2)

Abstract

A wide range of aromatic aldehydes has been selectively converted to 1,1-diacetates using silica chromate (SiO₂?O?CrO₂?O?SiO₂) under solvent-free conditions at room temperature in moderate to good yields. This protocol is mild and efficient compared to other reported methods.

GRAPHICAL ABSTRACT