Potassium-ferf-butoxide

The submitters employed alcohol-free potassium ferf-butoxide, purchased from K K Laboratories, without further purification the checkers employed comparable material taken from a freshly opened bottle purchased from MSA Research Corporation. The submitters report that among approximately ten different bottles of commercial potassium terf-butoxide used, only material from one bottle failed to form the tricarbonate in this procedure. The defective material in this one bottle was an extremely fine powder that failed to dissolve when... 

Similarly, sodium methoxide (NaOCHj) is a suitable base and is used in methyl alcohol. Potassium hydroxide in ethyl alcohol is another base-solvent combination often employed in the dehydrohalogenation of alkyl halides. Potassium ferf-butoxide [K0C(CH3)3] is the prefened base when the alkyl halide is primary it is used in either terf-butyl alcohol or dimethyl sulfoxide as solvent. 

Nucleophilic displacement of bromide from 5-acetyl-10-bromo-5//-dibenz[7>,/]azepine (41) by alkoxide,132 and by cyanide ion in dimethylformamide,212 has been noted. However, replacement of bromide by cycloalkylamines (e.g., piperidine) to give the 10-cycloalkylamino derivatives. e.g. 44, is best accomplished in the presence of potassium ferf-butoxide, a result which suggests that the aminodebromination proceeds via an elimination-addition (EA) pathway involving an azepyne intermediate 43 (see Section 3.2.1.5.7.) rather than by the more usual addition-elimination (AF.) mechanism.118... 

Potassium ferf-butoxide was purchased from Columbia Organic Chemicals Company, Columbia, South Carolina. The molar ratio of potassium ferf-butoxide to water is critical, and the amounts specified represent optimum quantities for cleavage of 0.10 mole of ketone.2,3... 

The present synthesis10 consists of two simple steps, uses readily available and inexpensive starting materials, and produces pure material in high overall yield. It is based on two observations that nonenolizable ketones may be cleaved to carboxylic acids by potassium ferf-butoxide-water,2 and that aryl 2 chlorophenyl ketones may be cleaved with loss of the 2-chlorophenyl group to give only one of the two possible acids.11 Other compounds prepared by this route include carboxycyclopentadienyltriearbonylmanganese [Manganese, tricar-bonyl[(l, 2,3,4,5- )-l-carboxy-2,4-cyclopentadien-l-yl]-] (79%)10 and... 

Potassium ferf-butoxide was supplied by Mine Safety Appliances (MSA) Research Corporation. 

B. Benzocyclopropene. A dry, three-necked, round-bottomed flask fitted with a sealed mechanical stirrer, a reflux condenser, and a pressure-equalizing dropping funnel is flushed with nitrogen. To the flask is added 35.0 g (0.312 mole) of potassium ferf-butoxide (Note 1), followed by 200 ml. of dimethyl sulfoxide (Note 5). The stirred mixture is cooled to 15-20° (Note 6) with an ice bath and 24.5 g. 

Potassium /ert-butoxide See Potassium ferf-butoxide Acids, etc. 

Addition of potassium ferf-butoxide or of sodium isopropoxide to the solvent led to ignition of the latter. This was attributed to presence of free metal in the alkoxides, but a more likely explanation seems to be that of direct interaction between the powerful bases and the sulfoxide. 

A previous method [1] of preparing 3,3-dimethylbutyne by dehydrochlorination of the title compound in a sodium hydroxide melt is difficult to control and hazardous on the large scale. Use of potassium ferf-butoxide as base in DMSO is a high-yielding, safe and convenient alternative method of preparation of the alkyne [2], See Dimethyl sulfoxide Metal alkoxides See other HALOALKANES... 

Mesityl oxide Methanol Methylamine N- M et hy lformam i de Methyl isobutyl ketone 2-Aminoethanol, chlorosulfonic acid, nitric acid, ethylenediamine, sulfuric acid Beryllium dihydride, chloroform, oxidants, potassium fcrf-butoxidc Nitromethane Benzenesulfonyl chloride Potassium ferf-butoxide... 

Di-0-isopropylidene-a-D-rtbo-hexofuranos-3-ulose (100) was treated with (chlorofluoromethylene)triphenylphosphorane (prepared by reaction of triphenylphosphine on difluorocarbene generated in situ by reaction of potassium ferf-butoxide with dichloro-fluoromethane), to give cis- and rans-3-C-(chlorofluoromethylene)-3-deoxy-l,2 5,6-di-0-isopropylidene-a-D-ribo- (101 and 103) and -xyfo-hexofuranoses (105 and 107), which, on treatment with lithium aluminum hydride, gave cis- and frans-3-deoxy-3-C-(fluoromethyl)-1,2 5,6-di-O-isopropylidene-a-D-rtbo- (102 and 104) and -xyZo-hexofura-... 

Alcohol-free potassium ferf-butoxide, obtained from the MSA Research Corporation, Callery, Pennsylvania, should be weighed and transferred under anhydrous conditions. 

Feuer and co-workers extended their studies to the alkaline nitration of a,Nitration with potassium ferf-butoxide and amyl nitrate in THF at —30 °C yields the corresponding dipotassium salt of the a,nitronate salts from these reactions are isolated via methanol-induced precipitation from the aqueous reaction liquors, a process which also separates the product from impurities. These salts undergo hydrolysis on treatment with aqueous potassium hydroxide, and subsequent acidification yields the corresponding Q, y-dinitroalkane. This route has been used to synthesize 1,4-dinitrobutane (27) from apidonitrile (95) in 30 % overall yield. 

Treatment of the Michael adducts 94 with a strong base such as potassium ferf-butoxide yielded the 2-azaazulenes 131 in 48-70% yield, respectively (Scheme 43) [60]. 

In all cases the reactions proceeded smoothly at - 78 °C and the alcohols 235 with an (k)-configuration at the newly formed stereogenic center were the major diastereomers in all cases. When the reaction mixtures were allowed to reach room temperature, mixtures of the alcohols 235 and the lactones 236 were isolated instead. The lactones 236 were exclusively obtained when the corresponding alcohols 235 were treated with potassium ferf-butoxide. On the other hand, treatment of the alcohols 235 with dilute hydrochloric acid afforded mixtures of the alkenes 237 and the tetracyclic compound 238, the structure of which was confirmed by X-ray analysis. 

Fluoromethane would presumably tend to react by an Sjv2 process rather than by deprotonation, whatever the base used. On the other hand, potassium ferf-butoxide ° and fluoride suffice already to set free the trilluoromethyl anion from trifiuoromethane (fiuoroform). Being extremely fragile, the trifluoromethanide must be trapped in situ, for example by addition to iV,iV-dimethylformamide. 

Reaction of N-acetyl-lO-bromodibenzazepine 51 with potassium ferf-butoxide yields the reactive intermediate 52 that reacts with N-methyl pyrrole 53 (X = NMe) used as a solvent to produce a mixture of Diels-Alder/retro Diels-Alder adduct 54 with the Michael by-product 55 (X = NMe, Scheme 10 (1994JHC293)). 

N -(2-Hydroxymethylphenyl)pyrrole is prone to selective a-metalation with fj-BuLi-potassium ferf-butoxide. Trapping the formed anion with a variety of electrophiles and treatment of the crude products with silica gel in toluene results in pyrrolo-benzoxazepines 266 and pyrrolo-benzoxazepinone 267 (Scheme 57 (1994T2071)). 

Similarly, methylation of pyrrolo-benzothiazepines 172 (Scheme 34, Section 2.3.1 (1994MI283)) and 307 (Scheme 66, Section 3.3.1.2 (2005FES385)) with methyl iodide in acetone in the presence of potassium carbonate proceeds regioselectively and produces N-methyl pyrrole derivatives as sole products. Methylation on the thiazepine ring nitrogen requires stronger base, i.e. potassium ferf-butoxide, to give dimethyl 174 and 311, respectively. 

The conventional and efficient method for the synthesis of dithienyl-maleimide 185, according Scheme 56, was described by Chinese researchers (06TL9227). 2,3-Bis(5-bromo-2-methylthiophen-3-yl)fumaronitrile 184 was hydrolyzed with sodium methoxide-methanol followed by N-meth-ylation with potassium ferf-butoxide and iodomethane to give the target compound 2,3-bis(5-bromo-2-methylthiophen-3-yl)-N-methylmaleimide. Subsequent modification of the latter afforded 186 containing two ferrocene fragments. 

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