Task specific ionic liquid as solvent,catalyst and reagent for regioselective ring opening of epoxides in water

Task specific ionic liquid as a novel and environmental eco-friendly green catalyst has been synthesized and used in the ring opening of epoxides under green conditions. This ionic liquids as solvent, catalyst and reagent afforded the corresponding thiocyanohydrins and azidohydrines with good regioselectivity and very short reaction times. The desired thiocyanohydrins and azidohydrines in 83–93% isolated yields.     

5-Bromobarbituric Acid : A Mild and Selective Monobrominating Agent Employed in the Synthesis of the Gastrin Antagonist GR174152

5-Bromobarbituric acid (5) is a convenient reagent for the selective bromination of cyclic imine 3. A facile, in situ synthesis of this reagent involving a disproportionation reaction between barbituric acid and dibromobarbituric acid is described.     

Spectrophotometric Determination of Palladium(II) With 2, 2′-Dipyridylglyoxime

Abstract

A spectrophotometric method is described for the determination of palladium with 2,2′-dipyridylglyoxime. The effects due to pH, time, solvents, reagent concentration and diverse ions are reported. A new method of reagent synthesis is also described.     

P2O5/SiO2 as an Efficient Reagent for the Preparation of Z -Aldoximes Under Solvent-Free Conditions

Abstract

A facile and efficient method for the preparation of Z-aldoximes is improved by means of P₂O₅/SiO₂ reagent in solvent-free media. Advantages of this method are the use of inexpensive and selective reagent, with high yields in simple operation, and short reaction time under solvent-free conditions.     

Spectrophotometric Determination of Palladium (11) With 2,2′-pyridilmonoxime

Abstract

A visible spectrophotometric method is described for the determination of palladium with 2,2′-pyridilmonoxime. The effects due to pH, time, solvents, reagent concentration and diverse ions are reported. Reasonable structures for the reagent and palladium chelate based on analysis and infrared evidence are proposed.     

The Development of Rotors Having Separate Sample and Reagent Transfer Channels for Use with Centrifugal Fast Analyzers

Abstract

Two new rotors have been designed and developed for use with Centrifugal Fast Analyzers. These rotors incorporate separate sample and reagent chambers and transfer channels, which prevent premature mixing of the aliquots of sample and reagent and also provide for their simultaneous and rapid transfer and mixing when the rotor is accelerated.     

Zinc hyperaccumulating plants as renewable resources for the chlorination process of alcohols

Abstract

Green Lucas reagent was prepared from Zinc hyperaccumulating plant, Thlaspi caerulescens. It is an effective and reusable reagent for the chlorination of tertiary, secondary, and primary alcohols. The results are the first use of contaminated biomass in organic synthesis and can constitute an encouragement for the economic development of phytoextraction and remediation programs for metal-bearing soils.     

NATURAL BENTONITE CLAY/DILUTE HNO3 (40%)—A MILD,EFFICIENT, AND REUSABLE CATALYST/REAGENT SYSTEM FOR SELECTIVE MONO NITRATION AND BENZYLIC OXIDATIONS

ABSTRACT

Selective mono nitration of Aromatic hydrocarbons and benzylic oxidations can be achieved in high yield using reusable catalyst/reagent system consisting of bentonite clay and dilute HNO₃ under relatively mild experimental conditions. The dual behavior of the catalyst reagent system is utilized for the regioselective synthesis of a variety of industrially important compounds.     

A Self-Coupling Diazotizing Reagent for Nitrite

Abstract

8-Amino-1-naphthol-5-sulfonic acid is proposed as a self-coupling diazotizing reagent for the determination of nitrite.     

PHOSPHORUS PENTASULFIDE AS A MILD,SELECTIVE REAGENT FOR THE REDUCTION OF SULFOXIDES TO SULFIDES

Abstract

It has been shown that phosphorus pentasulfide (P₄S₁₀) is a mild, effective reagent for the reduction of sulfoxides to sulfides and that this conversion can be achieved selectively in the presence of other reactive groups such as ketone, ester, amide, nitro and halogen. This reagent can be used in similar fashion for the efficient reduction of sulfilimines (in both the N-p-toluenesulfonyl and free NH forms). Phosphorus pentasulfide also appears to be a promising reagent for reducing selenoxides but is ineffective in reducing sulfones, sulfinates, or sulfites. The mechanistic evidence presented indicates a probable four-centre (Wittig-like) intermediate or transition-state for the reduction by P₄S₁₀.     

Colorlmetric Analysis of Malathion and Parathion Using Fluoboric Acid

Abstract

Monohydroxyfluoboric acid is described as a reagent for the determination of the organophosphorus compounds malathion and parathion. The reagent breaks the ether linkage to phosphorous to form a phosphoro-or phosphono-fluoridate which is then coloriraetrically determined by reaction with hydrogen peroxide and 2,7-diaroinofluorene. From 0.01 to 0.50 mg./ml. of the organophosphorus compounds can be determined.     

Ultramicro Analysis of Reducing and Non-Reducing Sugars by Liquid Chromatography

Abstract

A post-column detection system for ultramicro amount of sugars has been developed using taurocyamine as the labelling reagent. Less than 10 pmol of reducing sugars were determined by this HPLC system. Non-reducing sugars were detected by the addition of periodate to the reagent.

Modification of the reaction reagent components made this detection system feasible to apply to various methods for separation of carbohydrates using pure water, acetonitrile/water mixtures, borate buffer or aqueous sodium hydroxide as the eluent.     

Reaction of 2-Thioxo-4-Thiazolidinones Toward Lawesson's Reagent,Phosphorus Pentasulfide,Dialkylaminophosphines, and Phosphorus Ylides

Abstract

2-Thioxo—3-allyl-4-thiazolidinone 1a reacts with Lawesson's reagent (LR, 2) to give the ethylenic product 5 through a coupling reaction along with the dithioxo compound 6. Coupling reaction products of types 8 and 9 are also produced upon reacting thiazolidinones 1 and with the appropriate tris(diallkylamino) phosphine reagent (3 a,b). Reaction of the thiazolidinone 1a with the ylidenetriphenylphosphorane reagents 4 a–c proceeds according to the Wittig mechanism yielding ethylenes 10a–c, respectively. Structural elucidations for the new products were based upon compatible analytical and spectroscopic measurements as well a confirmatory single crystal X-ray structure for 5.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the related elements to view the free supplemental file.     

β-Naphthol as a Chromophore and Fluorophore Forming Reagent in the HPLC Determination of Alkyl Halides

Abstract

A suitable chromophore- and fluorophore- forming reagent for the detection of alkyl halide water contaminants is β-naphtol. The ether derivatives are separated from each other and excess β-naphthol reagent by reverse, phase HPLC and are detected by ultraviolet absorption or fluorescence. A method for the determination of alkyl halides is presented. The method is applicable to concentration levels in the ppm range for UV detection and in the ppb concentration range using fluorescence detection.     

Mercuric Nitrate‐Mediated Deprotection of Oximes,Hydrazones, and Semicarbazones

Abstract

Mercuric nitrate in wet silica gel is found to be an excellent reagent for the regeneration of carbonyl compounds from oximes, hydrazones, and semicarbazones.     

NEW PRODUCTS OF REACTION OF LAWESSON'S REAGENT WITH DIOLS

Reaction of the Lawesson's reagent (LR) with aliphatic 1,2- and 1,3-diols as well as with aromatic 2,2′-dihydroxybiphenyl led to new products. Stable di-tert-butylammonium salts of bis-anisyldithiophosphonic acids 6 were isolated and were then converted into unique 9-, 9-, and 10-membered cyclic disulfides 7 and into S,S-dimethyl esters 8. The salts of bis-anisyldithiophosphonic acids 6 were shown to be capable of splitting the disulfide bond of Ellman's reagent.     

The Preparative Scale Reverse Phase HPLC Separation of Epimeric Alkaloids Using Camphorsulfonic Acid as an Ion Pairing Reagent

Abstract

A reverse phase paired ion HPLC procedure is described for the separation of multigram quantities of epimeric alkaloids using camphorsulfonic acid as the ion-pairing reagent.     

TOTALLY SELECTIVE DRY MICROWAVE ASSISTED AMIDE SYNTHESIS BY HYDRATION OF NITRILE USING SILICA SUPPORTED MnO2 REAGENT

ABSTRACT

An easy, facile and efficient method for nitrile hydrolysis is developed using the combination of a silica supported MnO₂ reagent and microwave irradiation under dry reaction conditions.     

Oxidative Deprotection Of Trimethylsilyl and Tetrahydropyranyl Ethers and Ethylene Acetals With Benzyltriphenylphosphonium Peroxomonosulfate in the Presence of Bismuth Chloride Under Non-Aqueous Conditions

Abstract

Benzyltriphenylphosphonium peroxomonosulfate (BnPh₃P⁺HSO₅ ^?) (1) is used as a new reagent for oxidative deprotection of trimethylsilyl and tetrahydropyranyl ethers and ethylene acetals to afford carbonyl compounds in refluxing acetonitrile in the presence of bismuth chloride.