Ethanol from ethyl acetoacetate

The ethyl ester can also be prepared from ethyl acetoacetate (ethyl 3-oxobutanoate) by the method of Rodionov8 as well as via Steinkopf s method.3 Ethyl nitroacetate can be prepared in >70% yields from the dipotassium salt, ethanol, and sulfuric acid, with the addition of anhydrous magnesium sulfate in order to avoid the Nef reaction.9 The propyl and 2-propyl esters can also be obtained by this method. 

Copper derivative. Shake 0.2 g of the substance vigorously with a little cold, saturated, aqueous copper(n) acetate solution. Many ends give a solid, green or blue, copper derivative, which can be crystallised from ethanol and often has a definite m.p. (e.g. from ethyl acetoacetate, m.p. 192 °C from diethyl acetonedi-carboxylate, m.p. 142 °C. 

Methyluracil is prepared from ethyl acetoacetate and urea by a two-step process. Finely powdered urea ii itlrred Into ii mixture of small amounts of absolute ethanol and hydrochloric acid In a urystullizing dish which is placed in a... 

Dehydroacetic acid was first synthesised in 1866 ° it is formed very simply from ethyl acetoacetate by a Claisen condensation between two molecules, followed by the usual cyclisation and finally loss of ethanol. In a modem version, P-keto-acids can be self-condensed using carbonyl diimidazole as the condensing agent. ... 

Mix 6 2 ml. (6 4 g.) of pure ethyl acetoacetate and 5 ml. of pure phenylhydrazine in an evaporating-basin of about 75 ml. capacity, add 0 5 ml. of acetic acid and then heat the mixture on a briskly boiling water-bath (preferably in a fume-cupboard) for I hour, occasionally stirring the mixture with a short glass rod. Then allow the heavy yellow syrup to cool somewhat, add 30-40 ml. of ether, and stir the mixture vigorously the syrup may now dissolve and the solution shortly afterwards deposit the crystalline pyrazolone, or at lower temperatures the syrup may solidify directly. Note. If the laboratory has been inoculated by previous preparations, the syrup may solidify whilst still on the water-bath in this case the solid product when cold must be chipped out of the basin, and ground in a mortar with the ether.) Now filter the product at the pump, and wash the solid material thoroughly with ether. Recrystallise the product from a small quantity of a mixture of equal volumes of water and ethanol. The methyl-phenyl-pyrazolone is obtained... 

Gently warm a mixture of 32 g. (32 ml.) of ethyl acetoacetate and 10 g. of aldehyde-ammonia in a 400 ml. beaker by direct heating on a gauze, stirring the mixture carefully with a thermometer. As soon as the reaction starts, remove the heating, and replace it when the reaction slackens, but do not allow the temperature of the mixture to exceed 100-no the reaction is rapidly completed. Add to the mixture about twice its volume of 2A -hydrochloric acid, and stir the mass until the deposit either becomes solid or forms a thick paste, according to the quality of the aldehyde-ammonia employed. Decant the aqueous acid layer, repeat the extraction of the deposit with more acid, and again decant the acid, or filter off the deposit if it is solid. Transfer the deposit to a conical flask and recrystallise it twice from ethanol (or methylated spirit) diluted with an equal volume of water. The i,4-dihydro-collidine-3,5-dicarboxylic diethyl ester (I) is obtained as colourless crystals, m.p. 130-131°. Yield 12 5 g,... 

A simplified procedure is possible by using polyphosphoric acid as the condensing agent. Add 160 g. of polyphosphoric acid to a solution of 11 g. of resorcinol in 13 g. of ethyl acetoacetate. Stir the mixture and heat at 75-80° for 20 minutes, and then pour into ice-water. Collect the pale yellow solid by suction filtration, wash with a little cold water, and dry at 60°. The yield of crude 4-methyl-7-hydroxycoumarin, m.p. 178-181°, is 17 g. Recrystalbsation from dilute ethanol yields the pure, colourless compound, m.p. 185°. 

Al Preparation of 7-Hydroxy-4,8-Dimethy/coumarin Chilled ethyl acetoacetate (157 ml, 1.20 mols) followed by 2-methyl-resorcinol (130 g, 1.04 mols) was dissolved in well-stirred concentrated sulfuric acid (600 ml) at such a rate as to keep the temperature below 10°C (ice bath). The stirred solution was allowed to warm gradually and after 3 hours was added to water (ca 8 liters) with mechanical stirring. The product was collected, washed twice with water, and dried at 70° to 80°C until the first sign of darkening. Yield 191.3 g (95.4%). Recrystallization from aqueous ethanol gave 7-hydroxy-4,8-dimethylcoumarin as colorless needles, MP 260.5° to 261°C. In dilute sodium hydroxide, the compound gives a yellow solution which exhibits blue fluorescence. 

D-Glucose or D-mannose (100 g.) is well mixed in a mortar with 50 g. of anhydrous zinc chloride,470 and the mixture is transferred to a round-bottomed flask. Ethyl acetoacetate (50 g.) plus 50 ml. of 96% ethanol are added, and the stirred suspension is heated in a boiling water bath until homogeneous.48 The hot solution is poured into 300-400 ml. of ice plus water the product separates on standing, in the form of crystalline needles. It is filtered off and recrystallized three times from hot water yield, 30 g. m. p., 148-149°.4 - ... 

Other Methods of Preparation.—Ethyl 2-(D-ara6i no-tetrahydroxybutyl)-5-methyl-4-furoate has been prepared by heating D-glucose plus ethyl acetoacetate in aqueous alcohol without a catalyst,1 or from the same reagents (1 g. and 0.5 ml., respectively) in 0.5 ml. of 96% ethanol plus 1.5 ml. of water at room temperature in the presence of ferric chloride, zinc chloride (with small quantities of hydrochloric acid or of sodium hydroxide), cupric chloride, ferric sulfate, zinc sulfate, aluminum chloride, nickel chloride, or cobalt nitrate.18... 

To 16.3 g Na in 210 ml ethanol add 93 g ethyl-acetoacetate (ethyl-3-oxo-butanoate), heat to boil and add dropwise 92 g (II) over 20 minutes. Stir and reflux five hours and cool to precipitate. Filter, wash with ethanol and dissolve precipitate in 800 ml water. Cool to 0° C and slowly add 80 ml ice cold concentrated HC1 to precipitate. Filter, wash with water and ligroin to get about 108 g 6-carbethoxy-4,5-dihydro-olivetol (ID) (reciystallize from petroleum ether). To 104 g (III) in 260 ml glacial acetic acid at room temperature with good stirring, add dropwise over one hour 69 ml Bromine. Heat-four to five hours at 60° C, cool and add 300 ml water and let stand twelve hours. Oil separates which will precipitate on agitation and... 

Bis(ethanol)trifluoroborane, 4 144t Bis(ethyl acetoacetate) titanate, 25 91 Bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF), organic semiconductors from, 22 207... 

Copper (II) chloride proved to be a very efficient catalyst for the Biginelli reaction in the absence of solvent [27]. When ethyl acetoacetate, aldehydes and urea or thiourea were heated neat in the presence of copper (11) chloride, the Biginelli products were isolated, after recrystallization from hot ethanol, in high yields and purities (Scheme 7). 

Solid-phase synthesis of substituted pyrazolones 550 from polymer-bound /3-keto esters 549 has been described (Scheme 68) <2001EJ01631>. Trisubstituted pyrazole carboxylic acids were prepared by reaction of polymer-bound arylidene- or alkylidene-/3-oxo esters with phenylhydrazines <1999S1961>. 2-(Pyrazol-l-yl)pyrimi-dine derivatives were prepared by cyclocondensation of ethyl acetoacetate and (6-methyl-4-oxo-3,4-dihydropyrimi-din-2-yl)hydrazine with aromatic aldehydes <2004RJC423>. Reactions of acylated diethyl malonates with hydrazine monohydrochloride in ethanol afforded 3,4-disubstituted-pyrazolin-5-ones <2002T3639>. Reactions of hydrazines with A -acetoacetyl derivatives of (45 )-4-benzyloxazolidin-2-one (Evans oxazolidinone) and (2R)-bornane-10,2-sultam (Oppolzer sultam) in very acidic media gave pyrazoles retaining the 3(5)-chiral moiety <1999S157>. 

Derivation By reacting ethyl acetoacetate with aniline, and eliminating ethanol. Acetoacetanilide may also be prepared from aniline and diketene. 

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