Methanolic Potassium Hydroxide Research Articles

Preparation of Epon-embedded renal tissue for scanning electron microscopy.

A method for the preparation of Epon-embedded renal tissue for scanning electron microscopy (SEM) is described. This involves careful removal of Epon by potassium hydroxide in absolute methanol to expose the embedded kidney tissue. The method is simple and gives good surface morphology of the sectioned and trimmed surfaces of the tissue block. Both sectioned and intact glomeruli are well shown. The method also allows SEM observation of tubules and blood vessels.

A series of pyrazole adducts and pyrazolato derivatives of platinum(II) containing various chelating phosphines as ligands: Characterization, 1H and 31P{ 1H} NMR spectra

New pyrazolato derivatives of platinum(II) are isolated, (LL)Pt(pz) 2, A, [LL = Ph 2P(CH 2) nPPh 2 (n = 1, 2, 3, or 4), Ph 2PCH 2CH 2AsPh 2, (Ph 2AsCH 2) 2 or cis-Ph 2PCHCHPPh 2; pzH = pyrazole, 3,5-dimethyl,- 3,5-bis(trifluoromethyl)-, or 3,5-dimethyl-4-nitro-pyrazole] by reaction of (LL)PtCl 2 with pyrazole and potassium hydroxide in methanol. By protonation of A with fluoboric acid the corresponding pyrazole adducts, [(LL)Pt(pzH) 2][BF 4] 2, B, are obtained when pzH is 3,5-dimethylpyrazole. The properties of the compounds are discussed on the basis mainly of the NMR evidence; 31P data are related to the dimension of the PtP(C) nP ring (n = 1–4) and to the trans-influence of the pyrazolato and pyrazole ligand.

Base catalysed rearrangement of a spiro oxy-cope system and related studies: A new entry into perhydrophenalene and perhydroacenaphthylene systems

The spirovinyl carbinol 5 when treated with methanolic potassium hydroxide was found to rearrange to perhydrophenalene- 1,4-dione 6 via an anionic oxy-Cope rearrangement followed by an intramolecular Michael addition. The epimeric mixture of ketol acetates 15a and 15b was also found to rearrange to 2-hydroxy-2-methyl perhydroacenaphthylene-1,3-dione 16 on treatment with base.

Spectrophotometric Determination of Carbaryl in Grains

Abstract A method has been developed for determining carbaryl (1-naphthyl N-methyl carbamate) in grains, based on hydrolysis of carbaryl with methanolic potassium hydroxide to 1-naphthol, reaction with 4-aminophenazone in the presence of alkaline oxidizing agent, and spectrophotometric measurement at the absorption maximum at 475 nm. The relationship between absorbance and concentration is linear in the range of 0.5-20 μg/mL. The method can be applied to levels as low as 0.3 ppm carbaryl in grains.

Synthesis of some 5H‐benzo[a]phenoxazin‐5‐one derivatives

AbstractThe substituted 6‐bromo and 6‐chloro‐5H‐benzo[a]phenoxazin‐5‐ones, prepared by condensation of substituted 2‐aminophenols with 2,3‐dibromo or 2,3‐dichloro‐1,4‐naphthoquinone in methanolic potassium hydroxide solution, have been dehalogenated to substituted 5H‐benzo[a]phenoxazin‐5‐ones in the presence of sodium hydrosulfite dissolved in aqueous pyridine under nitrogen atmosphere.

Rapid method for the analysis of tobacco nicotine alkaloids

A rapid glass capillary gas chromatographic (GC) method for the analysis of the nicotine alkaloids of tobacco, including nicotine, nornicotine, myosmine, anabasine, anatabine and 2,3′-dipyridyl, was developed. The use of glass capillary GC methodology, coupled with nitrogen-specific detection, provided rapid, unambiguous alkaloid analysis. About 25 mg of cured tobacco and 1 ml of 0.05 M methanolic potassium hydroxide (containing the internal standard, 2,4′-dipyridyl) were placed in a standard 2-ml autosampler vial, and the vial was capped and placed in an ultrasonic bath for 15 min. A 1-μl volume was analyzed by glass capillary GC operating in the split-injection mode on a wall-coated Superox™-4 column. This simple procedure is compared with the previously reported Soxhlet extraction-packed column GC method and the Griffith still-colorimetric method. The application of the method for the analysis of alkaloids in various cured and green, budworm-resistant, tobaccos is discussed.

34] Parinaric acid from Parinarium glaberrimum

This chapter discusses the preparation of parinaric acid from Parinarium glaberrimum . α-Parinaric acid, is derived from the seed oil of P. glaberrimurn . cis-Parinaric acid and trans-parinaric acid and a number of their derivatives have been used in a wide range of applications as fluorescent probes. The freshly extracted oil is immediately dissolved in 300 ml of cool 5% potassium hydroxide in methanol containing BHT under an atmosphere of argon. Saponification of the oil is accomplished by gently reflexing the solution for 30 min with stirring. Stock solutions of parinaric acid in ethanol containing 0.001% BHT, stored at −20°, and flushed with argon each time they are opened, are stable for periods up to 2 years. Microliter aliquots of these solutions are appropriate for addition to aqueous biological preparations. For synthetic applications or long-term storage of large quantities of parinaric acid, one recommends that solutions of parinaric acid be frozen in benzene. It is found that pure, dry, parinaric acid is obtained by lyophilization of the solution.

Formation of 4-hydroxy-3-(α-hydroxybenzyl)-4-phenyl-2-pyrazolin-5-one from the interaction of 3,6-bis-(α-hydroxybenzyl)-s-tetrazine with potassium hydroxide in methanol

4-Hydroxy-3-(α-hydroxybenzyl)-4-phenyl-2-pyrazolin-5-one has been obtained from the reaction of methanolic potassium hydroxide with 3,6-bis-(α-hydroxybenzyl)-s-tetrazine and its structure proved by an alternative synthetic route. The mechanism of the rearrangement has been shown to involve a hydride transfer to a further tetrazine molecule which undergoes reduction to the dihydro-derivative.

Prepartion of sphingolipid fatty acid methyl esters for determination by gas—liquid chromatography

Sphingolipid faty acids are first convrted to a mixture of free acids and their n-butyl esters by heating the specimen at 82°C in aqueous butanolic hydrogen chloride; the butyl esters are then saponified with methanolic potassium hydroxide. After acidification and extraction into hexane, the fatty acids are extracted into a very small volume of aqueous trimethyl( m-trifluorotoylyl)ammonium hydroxide (TMTFTH) injection of an aliquot of the TMTFTH extract into the gas chromatograph yields the fatty acid methyl esters by pyrolytic methylation of the quartenary ammonium salts of the fatty acids. The preparation of a specimen ready for gas—liquid chromatographic(GLC) analysis with quantitative recovery of teh sphingolipid fatty acids can be accoomplished in less than 2 h. By comparison, none of a number of well-accepted techniques for the release of sphingomyelin fatty acids by hydrolysis or methanolysis released the fatty acids quantitatively in less than 3 h, and all required additional manipulations before GLC analysis.

ChemInform Abstract: PHOTO‐ AND THERMALLY‐INDUCED RADICAL REARRANGEMENTS OF HYPOIODITES OF 3α‐ AND 3β‐METHYL‐5‐CHOLESTEN‐3‐OLS IN THE PRESENCE OF MERCURY(II) OXIDE AND IODINE OR SILVER(II) OXIDE AND IODINE

AbstractBestrahlung oder Erhitzen der Cholestenole (Ia) oder (Ib) in Gegenwart von Iod [ ‐ Hypoiodite] und HgO liefert jeweils als Hauptprodukt das Umlagerungsprodukt (IIa) (daneben ‐ bei der Photoreaktion von (Ia) ‐ das Epimere (IIb)).

The reactions of ethyl-, vinyl-, and ethynyl(trichloromethyl)carbinols with aqueous and methanolic potassium hydroxide, thiourea, and cyanamide

The reactions of ethyl(trichloromethyl)carbinol, dimethyl(trichloromethyl)carbinol, (trichloromethyl)vinylcarbinol, ethynyl (trichloromethyl)carbinol, and 1,1,1,-triehloro-3-nonyn-2-ol have been studied with the following reagents. Methanolicpotassiumhydroxide: α-methoxy acids are formed in 70 and 79% yields with the ethyl- and vinylcarbinols respectively. Double bond migration to the conjugated position was observed with the vinylcarbinol. Thiourea: substituted 2-imino-4-thiazolidinones are formed in 27 to 66% yield with the first three carbinols with double bond migration in the case of the vinylcarbinol. Cyanamide: the saturated carbinols were converted to substituted ethy] 2-imino-4-oxo-1-imidazolidinecarboximidates in 30 to 60% yield. Aqueouspotassiumhydroxide: α-chloro acids were formed from the ethyl- and vinylcarbinols in 23 and 24% yields respectively, again with double bond migration in the case of the vinylcarbinol.The results are discussed in terms of the known parallel reactions with phenyl (trichloromethyl)carbinol, and provide information which illustrates the usefulness and defines the limits of certain known synthetic reactions when applied to the alkyl, alkenyl, and alkynyl trichloromethylcarbinols.

ChemInform Abstract: PSEUDOESTERS AND DERIVATIVES. PART 12. THE REACTION OF 3‐BROMO‐ AND 4‐BROMO‐5‐METHOXYFURAN‐2(5H)‐ONE WITH POTASSIUM HYDROXIDE IN METHANOL

Chemischer InformationsdienstVolume 11, Issue 39 Preparative Organic Chemistry ChemInform Abstract: PSEUDOESTERS AND DERIVATIVES. PART 12. THE REACTION OF 3-BROMO- AND 4-BROMO-5-METHOXYFURAN-2(5H)-ONE WITH POTASSIUM HYDROXIDE IN METHANOL F. FARINA, F. FARINASearch for more papers by this authorM. C. MAESTRO, M. C. MAESTROSearch for more papers by this authorM. R. MARTIN, M. R. MARTINSearch for more papers by this authorM. V. MARTIN, M. V. MARTINSearch for more papers by this authorF. SANCHEZ, F. SANCHEZSearch for more papers by this author F. FARINA, F. FARINASearch for more papers by this authorM. C. MAESTRO, M. C. MAESTROSearch for more papers by this authorM. R. MARTIN, M. R. MARTINSearch for more papers by this authorM. V. MARTIN, M. V. MARTINSearch for more papers by this authorF. SANCHEZ, F. SANCHEZSearch for more papers by this author First published: September 30, 1980 https://doi.org/10.1002/chin.198039117Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume11, Issue39September 30, 1980 RelatedInformation

Photo- and Thermally-induced Radical Rearrangements of Hypoiodites of 3α- and 3β-Methyl-5-cholesten-3-ols in the Presence of Mercury(II) Oxide and Iodine or Silver(II) Oxide and Iodine

Abstract Hypoiodites of 3α- and 3β-methyl-5-cholesten-3-ols in benzene containing mercury(II) oxide and iodine gave 3α,5-epoxy-6β-iodo-3β-methyl-A-homo-4-oxa-5α-cholestane in 50–66% yield on irradiation or heating in the dark. Some minor products including the 6α-epimer were also found. The corresponding reaction with silver oxide and iodine reagent gave the same epoxide in 52% yield, together with a low yield of 3,4-seco-3-methyl-3-oxo-5-cholesten-4-al. Hydrogenolysis of the 6β-iodide with Pd–C as a catalyst gave 3α,5-epoxy-3β-methyl-A-homo-4-oxa-5α-cholestane (52% yield), together with the 6α-epimer arising from isomerization. The former, on treatment with boron trifluoride etherate and acetic anhydride in benzene, was transformed into 2-acetyl-3-methyl-5-acetoxymethyl-4-oxa-5β-cholestan-2-one. This was converted into 2β-acetyl-3α,5-epoxy-3β-methyl-4-oxa-A-homo-5α-cholestane by the treatment with aqueous methanolic potassium hydroxide.

Assay method for urokinase activity by capillary-tube isotachophoresis using a synthetic substrate

Urokinae activity was determined by capillary-tube isotachophoresis using N- a-acetyl- l-lysine methyl ester as a synthetic substrate. The resulting N- a-acetyl- l-lysine was separated and detected isotachophoretically using methanolic potassium hydroxide solution adjusted to pH 5.32 by adding a-ketoglutaric acid as a leading electrolyte and methanolic betaine hydrochloride solution as a terminating electrolyte. The enzymatic reaction was stopped by addition of tannic acid and the resulting supernatant solution was injected into an isotachophoretic analyser. Linearity was observed at urokinase activities in the range 1–30 I.U. The urokinase activities in commercial products determined by the method were in good agreement with those determined by Walton's modified plate method. The coefficient of variation of the method was less than 3.4%.

Base catalyzed rearrangement of some bicyclic ketol acetates.

The ketol 3a and its acetate 3b when refluxed in methanolic potassium hydroxide (5%) were found to rearrange to 4-methyl-8-acetyl-5,6,7,8-tetrahydro-1-naphthol 4 . The epimeric acetate 3c also behaved likewise. A mechanism is suggested for the rearrangement.

12,13-Epoxy-C-nor-D-homosteroids. VII. Reaction of 11-Oxygenated 17α-Acetyl-12β,13β-epoxy-13-epietiojervanes with Boron Trifluoride Etherate and Potassium Hydroxide

Abstract The title compounds were treated with boron trifluoride etherate in benzene at room temperature. 11β-Hydroxy- and 11-oxo-12β,13β-epoxides (1 and 14) underwent cleavage of the epoxy group at C-13 by the acid treatment to give the corresponding fluorohydrins (2 and 5) as the respective major products, while the former (1) also afforded a 13β-pregnane derivative (3) with a normal steroid skeleton. On the other hand, several 11-oxygenated 12α, 13α- and 12β,13β-epoxides (17, 17a, 19, 21, 1, and 23) were treated with potassium hydroxide in aqueous methanol at room temperature. All epoxides gave the corresponding Δ13(17)-20-ketones, and only 11-hydroxy- and 11-acetoxy-12α,13α-epoxides (17, 19, and 17a) were further transformed into a 13α-pregnane derivative (12).

ChemInform Abstract: SYNTHESIS OF α‐AMINO‐β‐(CARBOXYMETHYLAMINO)BUTYRIC ACID FROM BIS(GLYCINATO)COPPER(II)

AbstractDie Addition von Acetaldehyd (II) an den Kupferkomplex (I) liefert den Komplex (III).

Synthesis and X-ray determination of the structure of 3-benzyl-7-methoxy-6-phenylimidazo[1,2-b]-s-tetrazines prepared by the action of potassium hydroxide in methanol on 3,6-dibenzyl-s-tetrazines

Compounds with the novel imidazo[1,2-b]-s-tetrazine structure have been obtained by the action of alkali in methanol on 3,6-dibenzyl-s-tetrazines, and their molecular structure has been confirmed by X-ray analysis.

Anodic oxidation as a general route to benzoquinone bis- and mono-acetals

Oxidation of a wide range of substituted 1,4-dimethoxybenzenes in methanolic potassium hydroxide at a platinum anode allows easy access to benzoquinone bisacetals and, by hydrolysis of the latter compounds, to the respective monoacetals.

Studies on the constituents of Anthriscus sylvestris Hoffm. II. On the components of the flowers and leaves (author's transl)

The essential oils of the flowers and leaves of Anthriscus sylvestris HOFFM. were examined. Phenol, o-cresol, eugenol, β-myrcene, d-limonene, γ-terpinene, p-cymene, benzyl alcohol, phenethyl alcohol, l-linalool, β-farnesene and d-sabinyl acetate were identified from the flowers, and phenol, cresol (o-, m-, p-), guaiacol, eugenol, p-cymene, α-pinene, β-myrcene, d-limonene, γ-terpinene, terpinolene, β-farnesene, cis-3-hexen-1-ol, benzyl alcohol, phenethyl alcohol, d-sabinyl acetate, l-α-fenchyl acetate and chrysanthenyl acetate were identified from the leaves. It was found that d-sabinol was converted into p-cymene and β-thujone when preserved in CHCl3, CCl4 and others, and by treatment with methanolic potassium hydroxide chrysanthenyl acetate into 4, 6, 6-trimethyl-3-cyclohexenecarbaldehyde. Luteolin, apigenin and caffeic acid were isolated from the flowers, and desoxypodophyllotoxin, stigmasterol, β-sitosterol, n-paraffins, n-alcohols, fatty acids and esters were isolated from the flowers and leaves.