Powdered Potassium Hydroxide Research Articles

Deshalogenation of Sovtol-10 Using a No-Destructive Method: Pilot Plant Design

A practical and efficient treatment of PCBs (polychlorinated biphenyls) in transformer oil by a chemical dechlorination process has been reported. The transformer oil containing commercial PCB mixtures Sovtol-10 was treated by the required amounts of PEG 400 (polyethylene glycol 400) and powdered potassium hydroxide (KOH), along with different reaction times. The reaction of PEG with PCBs under basic condition produces arylpolyglycols and potassium chlorine. The relative efficiencies of PCB treatment process were assessed in terms of destruction and removal efficiency (DRE, %). Under the experimental conditions of KOH/PEG molar ratio 1.2:1, KPEG/oil 22:1 and three hours of reaction at 90°C, average DRE of PCBs was approximately 99%, showing completely removal of PCBs containing 5-7 chlorines. In the sample remain the congeners 52 and 44 that are not reported as toxic by the WHO (World Health Organization). With the previously reported conditions the scale up of the process was realized.

ChemInform Abstract: Efficient Procedures for 1-Bromo-1,3-butadiene and 2-Bromo-1,3- butadiene.

Abstract Mixtures of Z- and E-1-bromo-1,3-butadiene in which the E- or Z- isomer predominates have been obtained in good yields by treating a mixture of Z- and E- 1,4-dibromo-2-butene (90% Z-isomer) or pure E-1,4-dibromo-2-butene, respectively, with powdered potassium hydroxide in high-boiling petroleum. 2-Bromo-1,3-butadiene was obtained in high yields by stirring a mixture of vinylacetylene, concentrated aqueous hydrogen bromide and copper(I) bromide.

Benzylation of N-phenyl-2-phenylacetamide under microwave irradiation

N-Phenyl-2-phenylacetamide was alkylated with benzyl chloride in the presence of powdered potassium hydroxide under microwave irradiation in a solvent-free system. The reactions were also performed in the presence of phase-transfer catalysts. The formation of N-, O- and C-products of alkylation was followed by gas chromatography. The N-product was found to be the main product under microwave irradiation. The O-product was obtained in higher yields when an excess of base and benzyl chloride was used.

Solvent-Free Conversion of alpha-Naphthaldehyde to 1-Naphthoic Acid and 1-Naphthalenemethanol: Application of the Cannizzaro Reaction

The Cannizzaro reaction is routinely covered in organic textbooks, but owing to the shortage of suitable procedures for the undergraduate teaching laboratory, this reaction is seldom performed in a first-year organic chemistry class. In this experiment, powdered potassium hydroxide and α-naphthaldehyde are heated under solvent-free conditions to produce 1-naphthoic acid and 1-naphthalenemethanol in 86% and 79% yields, respectively. The solvent-free nature of this procedure greatly reduces the quantity of waste generated by students relative to the typical solvent-based method of preparation.

Reaction of Adamantan‐2‐one with Acetonitrile in Basic Media.

Substituted acetonitriles containing an activated methylene group are capable of reacting with ketones in the presence of strong bases [1]. We have found that adamantan-2-one (I) reacts with acetonitrile in the presence of powdered potassium hydroxide and dicyclohexano-18-crown-6 to give 2-adamantylideneacetonitrile (II). Under these conditions, intermediate 2-(2-hydroxy-2-adamantyl)acetonitrile (III) readily undergoes dehydration to nitrile II which is obtained as the major product (up to 90%, according to the GLC data). The dehydration is favored by elimination of steric strain, which accompanies the transition from the sp-hybridized bridging carbon atom in hydroxy nitrile III to sp in II. 2-Adamantylideneacetonitrile (II) was synthesized previously by the Knoevenagel condensation of adamantan-2-one with cyanoacetic acid [2]. Nitrile II characteristically showed in the H NMR spectrum signals from nonequivalent protons in the bridgehead positions neighboring to the double bond ( 2.64 and 3.13 ppm).

Alkylation of N-substituted 2-phenylacetamides: Benzylation of N-(4-chlorophenyl)-2-phenylacetamide

Benzylation of N-(4-chlorophenyl)-2-phenylacetamidewith benzyl chloride in the presence of powdered potassium hydroxide under various reaction conditions was performed in order to establish the possible reaction products. Different temperatures and ratios of reactants and solvents were used. The reactions were also carried out in the presence of different phase-transfer catalysts in toluene as a solvent. The formation of the reaction products was followed using gas chromatography. On the basis of the obtained results, the reactivity and the orientation in the alkylation reaction of the investigated amide is discussed.

Reaction of Adamantan-2-one with Acetonitrile in Basic Media

Substituted acetonitriles containing an activated methylene group are capable of reacting with ketones in the presence of strong bases [1]. We have found that adamantan-2-one (I) reacts with acetonitrile in the presence of powdered potassium hydroxide and dicyclohexano-18-crown-6 to give 2-adamantylideneacetonitrile (II). Under these conditions, intermediate 2-(2-hydroxy-2-adamantyl)acetonitrile (III) readily undergoes dehydration to nitrile II which is obtained as the major product (up to 90%, according to the GLC data). The dehydration is favored by elimination of steric strain, which accompanies the transition from the sp-hybridized bridging carbon atom in hydroxy nitrile III to sp in II. 2-Adamantylideneacetonitrile (II) was synthesized previously by the Knoevenagel condensation of adamantan-2-one with cyanoacetic acid [2]. Nitrile II characteristically showed in the H NMR spectrum signals from nonequivalent protons in the bridgehead positions neighboring to the double bond ( 2.64 and 3.13 ppm).

Cobalt Phthalocyanine Catalyzed Aerobic Oxidation of Secondary Alcohols: An Efficient and Simple Synthesis of Ketones.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Cobalt phthalocyanine catalyzed aerobic oxidation of secondary alcohols: an efficient and simple synthesis of ketones

A variety of activated and non-activated secondary alcohols have been efficiently oxidized to their corresponding ketones in excellent yields with molecular oxygen using cobalt phthalocyanine as catalyst in the presence of powdered potassium hydroxide.

Alkylation of N-substituted 2-phenylacetamides: Benzylation of N-(4-nitrophenyl)-2-phenylacetamide

N-(4-Nitrophenyl)-2-phenylacetamide was alkylated with benzyl chloride in the presence of powdered potassium hydroxide at different temperatures and in various solvents in order to establish the reactivity and orientation in the reaction. The reactions were also carried out in the presence of different phase-transfer catalysts in toluene. Product formation was followed by GC. The obtained results were compared to the results of the benzylation of other N-substituted 2-phenylacetamides, especially of N-phenyl-2-phenylacetamide.

New Bis-indolic Macrolactams

Treatment of several ω-halogenoamides, derived from tryptamine, with powdered potassium hydroxide in 1,2-dimethoxyethane in the presence of 18-crown-6, resulted in intramolecular and/or bimolecular cyclization, depending on the length of the chain and dilution conditions, to give macrocyclic compounds. Some of them were converted by a Bischler-Napieralski reaction, followed or not by reduction, to new tetracyclic derivatives of β-carbolines.

Fast Nitroaldol Reaction Using Powdered KOH in Dry Media

Abstract β-Nitroalkanols are easily obtained within a few minutes, through the nitroaldol (Henry) reaction, catalyzed by a stoichiometric amount of powdered potassium hydroxide, in dry media. Satisfactory to excellent yields are obtained both with primary and secondary nitrocompounds, either with aromatic or aliphatic aldehydes.

An Improved Procedure for the Preparation of Aryl- and Hetarylacetylenes

A number of relatively volatile acetylenes RC≡CH (R = aryl or hetaryl) have been prepared with high yields by heating a mixture of the corresponding alcohols RC≡CC(CH3)2OH and paraffin oil with small amounts of powdered potassium hydroxide in vacuum. The alcohols were obtained by Pd/Cu-catalyzed cross coupling of aryl or hetaryl halides RX (X = Br, in one case I) with the commercially available HC≡CC(CH3)2OH.

Ethylsiloxane Oligomers Containing Organocyclosiloxane Fragments as a Lateral Group

Abstract The reaction and kinetic regularities of catalytic dehydrocondensation of oligoethylhydridsiloxane containing trimethylsiloxy end groups with hydroxyorganocyclosiloxanes in the presence of platinochlorohydric acid or anhydrous powdered potassium hydroxide has been studied. Ethylsiloxane oligomers containing various amounts of organocyclosiloxane fragments as lateral groups, completely soluble in organic solvents, has been synthesized. Reaction order, activation energy and dehydrocondensation rate constants were found. Thermogravimetric, thermomechanical and rentgenographic studies of synthesized oligomers were carried out.

Verbesserte präparative Darstellung von Polyisopropyl- und Poly-tert-butylcyclopentadienen / Improved Preparation of Polyisopropyl- and -tert-butylcyclopentadienes

Phase transfer catalytic isopropylation or tert-butylation of cyclopentadiene yields 1-6 in efficient one-pot procedures. Powdered potassium hydroxide or solid sodium hydride are the prefered bases, Aliquat 336 or dibenzo-18-crown-6 are the PT catalysts.

A Simple Synthetic Method for Tetraaza[3.3.3.3]meta- and paracyclopanes by Alkylation ofN-Substituted Trifluoroacetamide

A simple and practical synthesis of the title compounds (1b) and (2b) is described. Alkylation of N-substituted trifluoroacetamides (5a and b) with appropriate dibromides benzene(bis[bromomethyl]) (6 and 9), in the presence of sodium hydride in N,N-dimethylformamide at 100 o C, or powdered potassium hydroxide in refluxing acetone, followed by removal of the trifluoroacetyl group and N-methylation of the resultant amines provides the desired (1b) and (2b) in 21 and 19% overall yields, respectively, along with their lower and higher homologs

Synthesis of α-substituted and α,α-disubstituted α-amino acids by controlled mono- and dialkylation of ethyl N-diphenylmethyleneglycinate

Ethyl N-diphenylmethyleneglycinate reacts with one equivalent of alkylating agents in the presence of powdered potassium carbonate to afford, after hydrolysis, monoalkylated glycine esters. A similar process using two equivalents of alkylating agents in the presence of powdered potassium hydroxide and a phase transfer catalysts gives, after hydrolysis, dialkylated glycine esters.

Highly fluorinated heterocycles. Part XIX. Dehydrofluorination studies on 2-dipluoromethyl- and 2-trifluoromethyl-hexa- and -pentafluoro-oxolans

The four 3H, 4H-2-difluoromethylpentafluoro-oxolans reacted with powderedpotassium hydroxide in suspension in benzene to give 3H- (1) and 4H- (2)2-difluoromethyltetrafluoro-3,4-oxolen, different proportions being formedfrom each stereoisomer. 3H/4H- and 4H/JH-2-Trifluoromethylpentafluoro-oxolanslikewise afforded different proportions of 3H- (3) and 4H- (4) 2-trifluoromethyltetrafluoro-3,4-oxolen.From similar dehydrofluorinations of mixedisomers of 3H- and 4H- 2-difluoromethylhexafluoro-oxolan, there were formed2-difluoromethylpentafluoro-3,4- (5) and -2,3- (6) oxolen; mixed 3H- and4H-2-trifluoromethylhexafluoro-oxolan afforded an inseparable mixture of 2-trifluoromethylpentafluoro-3,4- (7a) and -2,3- (7b) oxolen. With cobalticfluoride, oxolen (5) gave 2-difluoromethylheptafluoro-oxolan (8). On treatmentwith aqueous potassium hydroxide, (8) underwent ring-opening, formingtetrafluoropent-2-en-l,5-diolc acid (10). Diels-Alder adducts resulted fromreactions of oxolen (Ta) with cyclopentadiene and with furan.

Efficient Procedures for 1-Bromo-1,3-Butadiene and 2-Bromo-1,3-Butadiene

Abstract Mixtures of Z- and E-1-bromo-1,3-butadiene in which the E- or Z- isomer predominates have been obtained in good yields by treating a mixture of Z- and E- 1,4-dibromo-2-butene (90% Z-isomer) or pure E-1,4-dibromo-2-butene, respectively, with powdered potassium hydroxide in high-boiling petroleum. 2-Bromo-1,3-butadiene was obtained in high yields by stirring a mixture of vinylacetylene, concentrated aqueous hydrogen bromide and copper(I) bromide.

Synthesis and antibacterial activity of some 1-(2-propynyl) and 1-propadienyl derivatives of 1,4-dihydro-4-oxoquinoline-3-carboxylic acids and similar heterocycles

N-Alkylation of IIIa, IIIb, IIId - IIIf and 9-acridanone with 3-bromopropyne in dimethyl sulfoxide in the presence of potassium carbonate yielded N-(2-propynyl) derivatives IVa - IVe and VIa, respectively. Ethyl esters IVa, IVb, and IVe were hydrolyzed to IVf - IVh, respectively. Compounds IVf, IVg, IVctreated with bases yielded N-propadienyl derivatives Va - Vc. On the other hand 2-substituted compounds IVd and IVh did not change under the same conditions. Compound VIa treated with powdered potassium hydroxide in dimethyl sulfoxide at room temperature yielded N-(1-propynyl) derivative VII.