Potassium condensations with

Trimethylene dibromide (1 mol) condenses with ethyl malonate (1 mol) in the presence of sodium ethoxide (2 mols) to form ethyl cydobutane-1 1-dksrboxylate (I). Upon hydrolysis of the latter with alcoholic potassium hydroxide, followed by acidification cyciobutane-1 1-dicarboxylic acid (II) is obtained. 

The condensation of aldehydes and ketones with succinic esters in the presence of sodium ethoxide is known as the Stobbe condensation. The reaction with sodium ethoxide is comparatively slow and a httlo reduction of the ketonic compound to the carbinol usually occurs a shorter reaction time and a better yield is generally obtained with the more powerful condensing agent potassium ieri.-butoxide or with sodium hydride. Thus benzophenone condenses with diethyl succinate in the presence of potassium [Pg.919]

Mesityl oxide (Section 111,79) (I) condenses with ethyl malonate in the presence of sodium ethoxide to give the sodium derivative of (II) this upon hydrolysis with aqueous potassium hydroxide, followed by acidification, gives the cyclic diketone 5 5-dimethyl-l 3-cycfohexanedione (III), of which the enoUc form is 5 5-dimethyldihydroresorcinol (IV) ... 

Ninhydrin (also named 1 2 3-triketoindane or 1 2 3-triketohydrindene hydrate) is prepared most simply from the inexpensive phthahc anhydride (I). The latter is condensed with acetic anhydride In the presence of potassium acetate to give phthalylacetlc acid (II) reaction of the latter with sodium methoxide in methanol yields 1 3-indanedionecarboxyhc acid, which is decomposed upon warming with dilute hydrochloric or sulphuric acid to indane-1 3-dione (or 1 3-diketohydrindene) (HI). Selenium dioxide oxidation of (III) afibrds indane-1 2 3-trione hydrate (ninhydrin) (IV). 

The potassium combines with the sulfur to form potassium sulfate, which condenses as a soHd primarily in the electrostatic precipitator (ESP) or baghouse. The recovered potassium sulfate is then deUvered to a seed regeneration unit where the ash and sulfur are removed, and the potassium, in a sulfur-free form such as formate or carbonate, is recycled to the MHD combustor. It is necessary also to remove anions such as Cf and E which reduce the electrical conductivity of the generator gas flow. These are present in the coal ash in very small and therefore relatively harmless concentrations. As the seed is recycled, however, the concentrations, particularly of CF, tend to build up and to become a serious contaminant unless removed. 

During operation, KCl is melted and introduced through a trap to the column. Molten sodium is fed to the bottom of the column. The lower portion of the column serves as a reactor, the upper portion as a fractionator. Potassium vapor is fractionated and condensed in an air-cooled condenser with the reflux pumped back to the top of the column. Waste sodium chloride is continuously removed from the bottom of the column through a trap. 

Isatin (190) is a compound with interesting chemistry. It can be iV-acetylated with acetic anhydride, iV-methylated via its sodium or potassium salt and O-methylated via its silver salt. Oxidation of isatins with hydrogen peroxide in methanolic sodium methoxide yields methyl anthranilates (81AG(E)882>. In moist air, O-methylisatin (191) forms methylisatoid (192). Isatin forms normal carbonyl derivatives (193) with ketonic reagents such as hydroxylamine and phenylhydrazine and the reactive 3-carbonyl group also undergoes aldol condensation with active methylene compounds. Isatin forms a complex derivative, isamic acid (194), with ammonia (76JCS(P1)2004). 

On oxidation by potassium hexacyanoferrate(III) adrenaline is converted into adrenochrome which then condenses with ethylenediamine ... 

In view of its possible interest as the mode of formation of harman, harmine and harmaline in plants, Kermack, Perkin and Robinson investigated the conversion of tryptophan (II) into harman (I) and nor-harman (IV). The latter is produced when tryptophan is condensed with formaldehyde in presence of dilute sulphuric acid and the product (III) oxidised by potassium dichromate. Harman is formed when formaldehyde in this process is replaced by acetaldehyde. 

Benzoin -As a small cjnantity of potassium cyanide is (apable of converting a large quantity of benzaldehyde into bciv/oin, the action of the cyanide has been explained as follows. The potassium cyanide first reacts with the aldehyde and forms a cyanhydnn, which then condenses with another molecule of aldehyde, hydrogen cyanide being finally eliminated (Lapwortbj,... 

In the synthesis of chuangxinmycin, Kozikowsld et al. employed the potassium salt of the acid 23 to condense with DMFDMA 6 to obtain the P-nitrostyrene 24 with the... 

Thiophenealdehydes have been condensed with aliphatic aldehydes, methyl ketones,cyclic ketones, " benzyl cyanides,and aliphatic nitro compounds to the corresponding vinylthiophenes. By the use of potassium methylate, 2-thiophenealdehyde has been condensed with the reactive methyl groups of iV-heterocyclic compounds. Thiophenealdehydes have... 

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. 

MalONIC ACID, ETHYLHYDROXY, DIETHYL ESTER, BENZOATE, 45, 37 Mfsitaidehydf, 47, 1 Mesitylcne, condensation with dichloro methyl methyl ether, 47, 1 Methalljl chloride in alkylation of 2,4-pentanedione with potassium carbonate, 47, 87... 

For the hydrolysis, accurately weigh approximately 2 g of the fat or oil into a 250 mL conical flask with a ground-glass joint and add 25 mL of the potassium hydroxide solution. Attach a reflux condenser and heat the flask contents on a steam bath for 1 h with occasional shaking. While the solution is still hot add phenolphthalein indicator and titrate the excess potassium hydroxide with the 0.5M hydrochloric acid (record as titration b mL). 

The first synthesis of a 3//-3-benzazepine, e.g. 65 (R1 = R2 = Me), was achieved by the condensation of phthalaldehyde with a bis[(alkoxycarbonyl)methyl]methylamine.24"25 With sodium methoxide as the base, A%V-bis[(methoxycarbonyl)methyl]pheiiylaniine condenses with the dialdehyde in a similar manner to give dimethyl 3-phenyl-3//-3-benzazepine-2,4-dicar-boxy late (65, Rl — Ph R2 — Me).99 However, replacement of methoxide by potassium tert-butoxide results in formation of 3-phenyl-3//-3-benzazepine-2,4-dicarboxylic acid (65, R1 = Ph R2 = H).25... 

The benzodiazepinone 26 condenses with 3-melhylbulyl nitrite (isopentyl nitrite) in the presence of potassium lerl-butoxide to give the oxime 27, which is converted into the amine 28 by catalytic hydrogenation.227... 

Base-induced eliminative ring fission, in which both the double bond and the sulfone function take part, has been observed in thiete dioxides253. The reaction can be rationalized in terms of initial Michael-type addition to the double bond of the ring vinyl sulfone, followed by a reverse aldol condensation with ring opening. The isolation of the ether 270c in the treatment of 6c with potassium ethoxide (since the transformation 267 -> 268 is not possible in this case) is in agreement with the reaction mechanism outlined in equation 101253. 

Generally, in the nucleophilic addition to carbonyl groups, either magnesium compounds or alkali metal compounds (such as the Li, Na and K derivatives) are used. In some cases even potassium carbonate or piperidine were used as the base for condensation with sulfones. Good results were obtained when concentrated aqueous NaOH was used under phase-transfer conditions288,297,333. 

Ny lon-6 (108 g) carpet backed with calcium-carbonate-filled latex and polypropylene was charged to a 1000-mL three-neck round-bottom flask (equipped with a condenser) with 6 mL of 85% phosphoric acid. Superheated steam was injected continuously during a 45-min period. The vapor temperature of the reaction medium was 250-300°C. The volume of distillate collected was 1065 mL. The distillate contained 1.9% e-caprolactam (as determined by GC), which corresponded to a crude yield of 37.5%. The distillate was fractionated in a distillation column and the nonaqueous phase removed. The remaining aqueous phase was treated with 2% potassium permanganate at 40-50°C for 2 h. Evaporation of... 

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