Methanolic Potassium Hydroxide

Fig. 4. Treatment of ivermectin with methanolic potassium hydroxide solution (25).

Phenylurea and A-phenyl-carbamate residues Apply sample solution, overspot with 7% methanolic potassium hydroxide, cover the start zone with a glass plate and heat to 170°C for 20 mm Primary arylamines are produced [41]... 

A solution of the epoxide in acetic acid at room temperature is heated under reflux for 2-3 hr. The reaction mixture is then cooled to ca. 40° and concentrated in vacuo to ca. 1/4 volume. The concentrate is diluted with water and extracted with ether. The ether extract is washed with an equal volume of water, dried (MgS04) and concentrated in vacuo. The crude or recrystallized product is then treated with an equal weight of mesyl chloride in dry pyridine at 0° for about 24 hr. A refluxing mixture of the mesylate and 25 % methanolic potassium hydroxide (wt/wt) affords the -epoxide. 

A variety of conditions has been used to prepare oxiranes from trans-hxomo-hydrins. In general, bromohydrins are heated in a solution of 5-10% methanolic potassium hydroxide for 30 min to 8 hr. Longer reflux times are required for bromohydrins which are not anti-coplanar, e.g., diequatorial bromohydrins. A 5 % solution of potassium acetate in boiling ethanol can be used to cyclize steroidal bromohydrins containing base sensitive groups. The use of 1.1 equivalents of sodium methoxide per equivalent of steroid in methanol solution is especially recommended for 9a-bromo-l lj5-hydroxy steroids. 

The present authors have found that the preparation of 7V-acetyl aziridine derivates provides the most secure method of differentiating aziridines from primary amines which are alternate reaction products in a number of cases. The infrared spectra of the former derivatives show only a peak at 1690 cm" for a tertiary amide peaks at ca. 3440 and 1530 cm" indicative of a secondary amide are absent. Acetylation also shifts the aziridine ring protons to a lower field in the NMR by ca. 1 ppm relative to the parent aziridine. The A"-acetyl aziridines are hydrolyzed with 3% methanolic potassium hydroxide. " Published NMR spectra of several 16j5,17j -aziridines reveal resonance patterns resembling those of the respective epoxides. " ... 

Chromatography of 3, 17jS-dihydroxypregn-5-en-20-one (82a) on alumina affords the rearranged product 3/ ,17a/ -dihydroxy-17aa-methyl-D-homo-androst-5-en-17-one (84a) in quantitative yield.On the other hand, treatment of diol (82a) or diacetate (82b) with methanolic potassium hydroxide... 

Water adds to the triple bond of perfluorobutylalkynols in refluxing 98% formic acid to give the perfluorobutyl keto alcohol Methanolic potassium hydroxide or prolonged reflux m formic acid converts the keto alcohol to 2,2-dimethyl-5-perfluoropropyl-2,2-dimethylturan-3(2//)-one [2] (equation 3). 

The halogens of halothiophenes are more labile than those of the corresponding benzenes in accordance with theoretical considera-tions which indicate that thiophenes should also undergo nucleophilic substitutions more rapidly than benzenes. Hurd and Kreuz" found that in qualitative experiments 3,5-dinitro-2-chlorothiophene was more reactive toward piperidine and methanolic potassium hydroxide than 2,4-dinitrochlorobenzene. A quantitative study on the reaction of the six isomeric bromonitrothiophenes with piperidine (Table V) shows that the thiophenes react about one thousand times... 

Another approach to the l-oxo-l,2-dihydro-j8-carboline system is that due to King and Stiller. When 2-ethoxy carbonyl-3-formyl-indole is condensed with hippuric acid the azlactone 162 is formed, which, with 10% methanolic potassium hydroxide, gives a mixture of the orthoester 163 and the potassium salt 164. 

Biimidazole and bibenzimidazole with [(ri -2-RC3H )Pd(p-Cl)]2 (R = H, Me) taken in the 2 1 molar ratio in the presence of methanolic potassium hydroxide give complexes of the type 146 (83JCS(D)1729) and with [(ti -2-RC3H ) Pd(Mc2C0) ](C10 ) - 147. When the ratio of 2,2 -biimidazole or 2,2 -bibenz-imidazole and [(Ti -2-RC3H )Pd(p-Cl)]2 (R = H, Me) is 1 1, the homo-tetranuclear species 148 result. Heterotetranuclear palladium(II)-rhodium(I) complexes 149 (L2 = cod) follow from [(TiLcod)Rh(Hbim)] and [(ri -2-R-C3H )Pd(acac)]. They are readily carbonylated with complete substitution of... 

This was reacted with chlorine to give the dichloropregnene compound, then with selenium dioxide to give the dichloropregnadiene compound. By hydrolysis with methanolic potassium hydroxide there was obtained the free 6a-fluoro-9a,11/3-dichloro-A -pregnadiene-16a,-17a,21-triol-3,20-dione. By treatment with acetone in the presence of perchloric acid, the 16,17-acetonide of 6a-fluoro-9a,11/3-dichloro-A -pregnadiene 16a,17a,21-triol-3,20-dione was formed. 

It is dissolved in hot methanol and heated on the steam bath with 10% methanolic potassium hydroxide solution (15.8 ml) for 10 minutes. Then more potassium hydroxide solution (2 ml) is added, the solution is cooled and on dilution with water a solid (II), MP 245° to 255°C, is obtained. A second crop is obtained from the mother liquors. Several recrystalli2ations from acetone yield an analytical sample, MP 262° to 265°C, [oIq is -2.1°. 

Hydroxydeethoxylation of the 2>H- -benzazepine 3 in refluxing methanolic potassium hydroxide (Method A) is accompanied by selective hydrolysis and loss of the 3-carboxylate group.20 Hydrolysis in concentrated hydrochloric acid, however, is rapid and yields only the bcnz-azepinone 4 (Method B). 

Pyrazolotriazine 253 was prepared (88JOC887) by coupling 3-diazopyrazole 250 with isopropylidene malonate 251 via 252. Methylation of253 with methyl iodide in the presence of methanolic potassium hydroxide gave pyrazolotriazines 255 and 256, whereas mono N-methyl derivative 254 was prepared (88JOC887) by the action of dimethyl sulfate on 253 (Scheme 55). 

Collection of Nonsaponifiable Lipids. Two hundred ants from the 2-C14-acetate feeding were ground with sand and the resulting brei refluxed for 4 hours in 25 ml. of ethanol, ethanol-diethyl ether (3 to 1), and diethyl ether (twice). The extracts were pooled, the solvents were evaporated, and the residue was saponified by refluxing for 1 hour with 20 ml. of methanolic potassium hydroxide (10% potassium hydroxide in 60% aqueous methanol). An equal quantity of water was added and the aqueous solution extracted three... 

Note It is occasionally recommended that after it has been sprayed the plate should be covered with a glass plate for several minutes until optimum reaction has occurred [11], or be irradiated with long-wavelength UV light (X = 365 nm) [2]. Methanolic potassium hydroxide solution can also be used in place of sodium hydroxide [12] (see Potassium Hydroxide Reagent). The formation of colors and fluorescences depends on the length of heating and on the temperature employed optimum conditions must be discovered empirically [12]. 

Changing the carbon disulfide trapping agent from copper acetate and diethylamine solution to methanolic potassium hydroxide to produce a xanthogenate increases the method s reproducibility and sensitivity. " ... 

Davidow (19), of the Food and Drug Administration, has described a colorimetric method applicable to technical chlordan. The method is based on the observation that when technical chlordan is heated with a mixture of diethanolamine and methanolic potassium hydroxide, a purple color is produced. When known amounts of this insecticide were added to cabbage, pears, and fresh and rancid rat fat, recoveries of 74 to 104% of the insecticide were obtained. However, because two crystalline isomers of chlordan isolated from the technical product do not give a colored reaction product with the reagent, further investigation of the method is being made. The red color obtained when technical chlordan is heated with pyridine, alcoholic alkali, and ethylene glycol monoethyl ether, as described by Ard (2), likewise fails with the crystalline isomers of this insecticide. 

Condensation of 2-ethynylcyclohex-l-eneylcarbaldehyde 69 with an excess of acetone gave the ketone 544 Reaction of equimolar amounts of 85 and 86 in ethereal methanolic potassium hydroxide gave the ketone 87. Oxidative coupling of 87 under Glaser conditions afforded two separable isomeric bisdehydro[15]-annulenones 88 and 89. The mono-ds isomer 88 may have the structure 90 in which... 

An interesting example of participation from a benzoyl group in the ester [29], having a conformationally rigid benzobicyclo[3.3.1]nonene structure, was reported in 1966 (Ghatak and Chakravarty, 1966). The ester [29] was rapidly hydrolysed in 1% methanolic potassium hydroxide at reflux. The esters [30], without a carbonyl group, and [31], isomeric to [29], were... 

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