Catalyst potassium acetate

Alternatively, use the following procedure in which triethylamine replaces potassium acetate as the basic catalyst. Place 2 1 g. (2-0 ml.) of purified benzaldehyde, 2 0 ml. of anhydrous triethylamine and 5 0 ml. of A.R. acetic anhydride in a 200 ml. round-bottomed flask, equipped with a short reflux condenser and a calcium chloride drying tube. Boil the solution gently for 24 hours—heating may be interrupted. Incorporate a steam distillation apparatus in the flask and steam distil until the distillate is no longer cloudy (about 100 ml.) and then collect a further 50 ml. of the distillate di ard the steam distillate. Transfer the residue in the flask to a 400 ml. beaker, add water until the vplume is about 200 ml., then 0 2 g. of decolourising carbon, and boil for a few minutes. Filter the hot solution, and acidify the hot filtrate with 1 1 hydrochlorioiaoid... 

Chemical Properties. Trimethylpentanediol, with a primary and a secondary hydroxyl group, enters into reactions characteristic of other glycols. It reacts readily with various carboxyUc acids and diacids to form esters, diesters, and polyesters (40). Some organometaUic catalysts have proven satisfactory for these reactions, the most versatile being dibutyltin oxide. Several weak bases such as triethanolamine, potassium acetate, lithium acetate, and borax are effective as stabilizers for the glycol during synthesis (41). 

The metals are impregnated together or separately from soluble species, eg, Na2PdCl4 and HAuCl or acetates (159), and are fixed by drying or precipitation prior to reduction. In some instances sodium or potassium acetate is added as a promoter (160). The reaction of acetic acid, ethylene, and oxygen over these catalysts at ca 180°C and 618—791 kPa (75—100 psig) results in the formation of vinyl acetate with 92—94% selectivity the only other... 

Strong bases, such as potassium acetate, potassium 2-ethylhexoate, or amine—epoxide combinations are the most useful trimerization catalysts. Also, some special tertiary amines, such as 2,4,6-tns(A7,A7-dimethylarninomethyl)phenol (DMT-30) (6), l,3,5-tris(3-dimethylaminopropyl)hexahydro-j -triazine (7), and ammonium salts (Dabco TMR) (8) are good trimerization catalysts. 

Cellulose dissolved in suitable solvents, however, can be acetylated in a totally homogeneous manner, and several such methods have been suggested. Treatment in dimethyl sulfoxide (DMSO) with paraformaldehyde gives a soluble methylol derivative that reacts with glacial acetic acid, acetic anhydride, or acetyl chloride to form the acetate (63). The maximum degree of substitution obtained by this method is 2.0 some oxidation also occurs. Similarly, cellulose can be acetylated in solution with dimethylacetamide—paraformaldehyde and dimethylformamide-paraformaldehyde with a potassium acetate catalyst (64) to provide an almost quantitative yield of hydroxymethylceUulose acetate. 

Benzal chloride is hydrolyzed to benzaldehyde under both acid and alkaline conditions. Typical conditions include reaction with steam in the presence of ferric chloride or a zinc phosphate catalyst (22) and reaction at 100°C with water containing an organic amine (23). Cinnamic acid in low yield is formed by heating benzal chloride and potassium acetate with an amine as catalyst (24). 

The isocyanurate reaction occurs when three equivalents of isocyanate react to form a six-membered ring, as shown in the fifth item of Fig. 1. Isocyanurate linkages are usually more stable than urethane linkages. Model compound studies show no degradation of the trimer of phenyl isocyanate below 270°C [10,11]. Catalysts are usually needed to form the isocyanurate bond. Alkali metals of carboxylic acids, such as potassium acetate, various quaternary ammonium salts, and even potassium or sodium hydroxide, are most commonly used as catalysts for the isocyanurate reaction. However, many others will work as well [12]. 

Reduction of unsaturated carbonyl compounds to the saturated carbonyl is achieved readily and in high yield. Over palladium the reduction will come to a near halt except under vigorous conditions (73). If an aryl carbonyl compound, or a vinylogous aryl carbonyl, such as in cinnamaldehyde is employed, some reduction of the carbonyl may occur as well. Carbonyl reduction can be diminished or stopped completely by addition of small amounts of potassium acetate (i5) to palladium catalysts. Other effective inhibitors are ferrous salts, such asferroussulfate, at a level of about one atom of iron per atom of palladium. The ferrous salt can be simply added to the hydrogenation solution (94). Homogeneous catalysts are not very effective in hydrogenation of unsaturated aldehydes because of the tendencies of these catalysts to promote decarbonylation. 

Filtration of the catalyst over a Hyflo pad and removal of the solvent left a yellow crystalline residue. The crude mixture of ketone and potassium acetate was partitioned between methylene chloride (300 cc) and water (1 liter), The layers were separated and the water layer washed with methylene chloride (3 x 50 cc). The organic layers were combined, washed with 3N sodium hydroxide solution (2 x 50 cc), water (3 x 100 cc), dried over anhydrous sodium sulfate and filtered. The solvent was removed and the product recrystallized from ethanol to give 2-amino-2 -fluorobenzophenone as yellow prisms melting at 126° to 128°C,... 

As previously discussed, solvents that dissolve cellulose by derivatization may be employed for further functionahzation, e.g., esterification. Thus, cellulose has been dissolved in paraformaldehyde/DMSO and esterified, e.g., by acetic, butyric, and phthalic anhydride, as well as by unsaturated methacrylic and maleic anhydride, in the presence of pyridine, or an acetate catalyst. DS values from 0.2 to 2.0 were obtained, being higher, 2.5 for cellulose acetate. H and NMR spectroscopy have indicated that the hydroxyl group of the methy-lol chains are preferably esterified with the anhydrides. Treatment of celliflose with this solvent system, at 90 °C, with methylene diacetate or ethylene diacetate, in the presence of potassium acetate, led to cellulose acetate with a DS of 1.5. Interestingly, the reaction with acetyl chloride or activated acid is less convenient DMAc or DMF can be substituted for DMSO [215-219]. In another set of experiments, polymer with high o -celliflose content was esterified with trimethylacetic anhydride, 1,2,4-benzenetricarboylic anhydride, trimellitic anhydride, phthalic anhydride, and a pyridine catalyst. The esters were isolated after 8h of reaction at 80-100°C, or Ih at room temperature (trimellitic anhydride). These are versatile compounds with interesting elastomeric and thermoplastic properties, and can be cast as films and membranes [220]. 

Pd-catalyzed asymmetric allylic alkylation is a typical catalytic carbon-carbon bond forming reaction [ 126 -128]. The Pd-complex of the ligand (R)-3b bearing methyl, 2-biphenyl and cyclohexyl groups as the three substituents attached to the P-chirogenic phosphorus atom was found to be in situ an efficient catalyst in the asymmetric allylic alkylation of l-acetoxy-l,3-diphenylprop-2-en (4) with malonate derivatives in the presence of AT,0-bis(trimethylsilyl)acetamide (BSA) and potassium acetate, affording enantioselectivity up to 96% and quantitative... 

The chemistry of vinyl acetate synthesis from the gas-phase oxidative coupling of acetic acid with ethylene has been shown to be facilitated by many co-catalysts. Since the inception of the ethylene-based homogeneous liquid-phase process by Moiseev et al. (1960), the active c ytic species in both the liquid and gas-phase process has always been seen to be some form of palladium acetate [Nakamura et al, 1971 Augustine and Blitz, 1993]. Many co-catalysts which help to enhance the productivity or selectivity of the catalyst have appeared in the literature over the years. The most notable promoters being gold (Au) [Sennewald et al., 1971 Bissot, 1977], cadmium acetate (Cd(OAc)j) [Hoechst, 1967], and potassium acetate (KOAc) [Sennewald et al., 1971 Bissot, 1977]. 

Potassium acetate, for example, can be readily alkylated by the use of an equivalent amount of an alkylating reagent (for example, an alkyl halide) in the presence of the phase-transfer catalyst Aliquat 336 (10 mol%) (Scheme 4.7) [16]. Yields are always near quantitative within a few minutes of microwave irradiation, irrespective of the chain length and the nature of the leaving group. This procedure has been scaled-up from 50 mmol to 2 mol scale in a large batch reactor [17]. 

Sodium methylate, potassium acetate, and piperidine were also applied as catalysts in the reactions of amidines and dialkyl malonates (53USP2638480). 

Methyldihydrocodeinone. A solution of bromomethyldihydrocodeinone (18.2 g) in 200 cc of 2 N acetic acid with 5 g of potassium acetate, a small amount of gum aribic, and 10 cc of 1% palladius chloride solution, was hydrogenated (see reductions chapter for instructions to hydrogenate). Remove the catalyst by filtration, make alkaline with NaOH, and extract with small portions of ether until a total of 2 liters is used. Combine the ether extracts, wash thoroughly with dilute alkali, and filter off the 12 g of white crystalline product. Recrystallize with ether or ethyl acetate to get mp of 144-144.5°. 

The nucleophilic displacement reaction of benzyl chloride with solid potassium acetate in various solvents under solid/solid/liquid conditions was faster with the polymer-bound catalyst 57 than with the soluble analog 58 181) (See Eq. (13)). 

Catalysts synthesized from crown ether monomers 61 and 62 by copolymerization with styrene and either p-divinylbenzene or p,p -divinylbiphenyl (63) are listed in Table 14 along with their relative activities for solid/solid/liquid reactions of potassium acetate with benzyl chloride (Eq. (13)) and potassium cyanide with 1,4-dichlorobutane (Eq. (14)) in acetonitrile 183). 

Numerous examples of solid/solid/liquid phase transfer catalysis are now known to be useful synthetically but have not been investigated mechanistically. Poly(ethylene glycol) immobilized on alumina and silica gel is active for reaction of solid potassium acetate with 1-bromobutane 184). Some of the best synthetic results with polymer supports are shown in Table 15. Often use of other solid salts or other catalysts gave poorer yields. It would be valuable to know for the design of future syntheses how these reactions depend on the partial solubility of the inorganic salts in the organic solvents and on the presence of trace amounts of water. 

Alkaline condensation of 4-isopropylbenzaldehyde and propanal results, via the aldol, in the formation of 2-methyl-3-(4-isopropylphenyl)-2-propenal. The unsaturated aldehyde is hydrogenated selectively to the saturated aldehyde in the presence of potassium acetate and a suitable catalyst, such as palladium alumina [150] ... 

Peracetic acid decomposition kinetics in the presence of cobalt or copper acetates were studied in the same apparatus used for the manganese-catalyzed reaction. However, in these studies it was used as a batch reaction system. The reactor was charged with peracetic acid (ca. 0.5M in acetic acid) and allowed to reach the desired temperature. At this time the catalyst (in acetic acid) was added. Samples were withdrawn and quenched with potassium iodide at measured time intervals. 

The gas-phase process, successfully commercialized independently by Bayer and USI,417 involves passing a mixture of ethylene, acetic acid and oxygen over a supported palladium catalyst contained in a multitubular reactor at 150 °C and about 5-10 atm pressure. The overall yield in vinyl acetate is about 92%, and the major by-product is C02. The catalyst consists of a palladium salt (e.g. Na2PdCl4) deposited on silica (or alumina) in the presence of a cocatalyst (e.g. HAuC14), reduced and impregnated with potassium acetate before use.384,418 The lifetime of the catalyst is about 2... 

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