Potassium hydroxide-dimethyl sulfoxide

Physical Data see entries for potassium hydroxide and dimethyl sulfoxide KOH/DMSO has pAa of 27 or higher.  

Alkylation of Amides, Phenols, Alcohols, and Adds. A variety of carboxamides were alkylated with primary alkyl halides using KOH in DMSO to give the fYalkyl amides (eq 1) in 54—90% yield. Most reactions were carried out at rt, but in some cases heating to 90 °C was required. Similar conditions were applied to alcohols, phenols, and acids to form ethers and esters. The procedure applies to Mel and all primary halides. Secondary alkyl halides show evidence of competitive dehydrohalogenation, while tertiary halides do not give any alkylation products. The procedure was applied to the N- and O-permethylation of peptides. It was also applied to the methylation of hydroxypyridines in 39-78% yield. In all the above cases, the substrate and alkyl halide were added to powdered KOH in DMSO and stirred at rt. It was unnecessary to use especially dry DMSO or to protect the reaction mixture from atmospheric moisture. 

A AU lation of Indoles and Pyrroles. fYAlkyl indoles and pyrroles were prepared in high yields (85-95%) hy reaction of indoles and pyrroles with primary alkyl hahdes in DMSO and powdered KOH at rt (eq 2). The yields were lower with secondary halides (60% for AAisopropylindole), while tertiary hahdes gave no alkylation products.  

Alkylation of Ketones. Ketones can be permethylated with iodomethane in DMSO containing solid KOH. Cyclobutanone, cyclopentanone, and indanone gave the corresponding tetramethyl ketones in 49, 90, and 75% yields, respectively. All reagents can be used without drying and KOH can be used as pellets or as a powder.  

Synthesis of 0-Arylhydro iylamines. Reaction of tricarbo-nylchromium complexes of aryl halides (1) with TYf-butoxycarbo-nylhydroxylamine (2) in DMSO and powdered KOH under N2 at rt resulted in the nucleophilic substitution of the Cl to give the corresponding tricarbonyl[(/-butoxycarbonylaminoxy)arene]chro-mium complexes (3) (eq 3). Consecutive I2 treatment and acid hydrolysis gave the O-arylhydroxylamines in high overall yields.  

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Potassium diphenyl-4-pyridylinetliide, 384 Potassium ferricyanide, 385 Potassium fluoride, 176, 266, 311, 323, 373 Potassium hexamethyldisilazide, 385-386 Potassium hydride, 386-387 Potassium hydride-18-Crown-6, 387 Potassium hydroxide, 387 Potassium hydroxide-Dimethyl sulfoxide, 388... 

Benedict, D. R., Bianchi, T. A., Cate, L. A. Synthesis of simple unsymmetrical ethers from alcohols and alkyl halides or sulfates the potassium hydroxide/dimethyl sulfoxide system. Synthesis 1979,428-429. 

Under the correct conditions cyclopropanecarboxylic acids have been obtained by cleavage of various cyclopropyl ketones using ozone, potassium permanganate " and potassium hydroxide/dimethyl sulfoxide as reagents. Bromine under basic conditions was successful when the substrates were acetylcyclopropanes, but the yield varied from low to excellent. ... 

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