Ethyl acetoacetate benzene

In a 1-L rbf attached to a Dean-Stark trap, equipped with a reflux condenser is placed distilled aniline (1, 46.5 g, 45.5 mL, 0.5 mol), commercially available ethyl acetoacetate (5, 65 g, 63.5 mL, 0.5 mol), benzene (100 mL) and glacial AcOH (1 mL). The flask is heated at about 125 °C, and the water which distills out of the mixture with the refluxing benzene is removed at intervals. Refluxing is continued until no more water separates (9 mL collects in about 3 hrs) and then for an additional 30 min. The benzene is then distilled under reduced pressure, and the residue is transferred to a 125 mL modified Claisen flask with an insulated column. The flask is heated in an oil or metal bath maintained at a temperature not higher than 120 °C while the forerun of 1 and 5 is removed and at 140-160 °C the product distills giving 78-82 g, 76-80% yield of 6. 

From Table 3, it can be seen that the reactivity of acyl acetanilide, such as BAA or AAA, is higher than that of the other reductant reported from our laboratory, i.e., acetanilide (AA), N-acetyl-p-methylaniline (p-APT), acetylacetone (AcAc), and ethyl acetoacetate (EAcAc). Moreover, the promoting activities of derivatives of acetoacetanilide were affected by the ortho substituent in benzene ring, and the relative rate of polymerization Rr) decreased with the increase of the bulky ortho substituent to the redox reaction between Ce(IV) ion and substituted acetoacetanilide. 

Ethyl acetoacetate affords a mixture of 19c and the benzimidazolone 20 under these conditions 272-273 however, only the benzodiazepinonc 19c is formed in the reaction of benzene-1,2-diamine with diketene (see Houben-Weyl, Vol. 7/4, p 236).274... 

A solution of pyridine-3,4-diamine (2.5 g, 23 mmol) and ethyl acetoacetate (4.55 g, 35 mmol) in toluene (180 mL) was refluxed for 5 h with azeotropic removal of H20. A mixture of I0A and I0B separated as a solid (2.42 g. 60%). Fractional recrystallization from benzene, followed by MeCN and finally EtOH/ cyclohexane gave 2-methyl-3//-pyrido[3.4-A][1,4]diazepin-4(5//)-one (10A) bright-yellow crystals mp 180-182 C. The more soluble component was 2-methyl-1 //-pyrido[3,4-6] 1,4]diazepin-4(5//)-one (10B) pale-yellow crystals mp 168-171 °C (benzene). 

Glycolaldehyde is formed by heating 2 g. of dihydroxymaleic acid in 10 ml. of water until the evolution of carbon dioxide ceases. To the resultant solution is added 2 ml. of ethyl acetoacetate followed by 2 ml. of ethyl alcohol and 1 g. of zinc chloride. The mixture is heated for one hour on a steam bath, and the reaction mixture is extracted with benzene. The benzene extract is washed with a concentrated solution of sodium bisulfite, and evaporated, affording an oil which is saponified by heating with sodium hydroxide solution (10%) on a steam bath for one hour. It is then acidified with dilute hydrochloric acid and extracted with ether. The ethereal extract is dried with anhydrous sodium sulfate and the solvent is evaporated the residue crystallizes from ether m. p., 99°. 

A mixture of 4.5 g. of 1-hydroxy-2-propanone, 80 ml. of ethyl acetoacetate, 60 ml of 96% ethyl alcohol, and 4 g. of anhydrous zinc chloride is heated under reflux on a steam bath for half an hour. After cooling, it is poured into water and extracted with benzene. The extract is washed successively with a bisulfite solution (twice), dilute aqueous sodium hydroxide, and dilute hydrochloric acid, and is dried over anhydrous sodium sulfate. The benzene is evaporated, giving 4 g. of an almost colorless oil which is saponified by heating with 5 g. of sodium hydroxide in 20 ml. of 96% alcohol for half an hour on a steam bath. Part of the alcohol is evaporated, water is added, and the solution is extracted twice with ether. The aqueous layer is acidified (to Congo Red) with hydrochloric acid (1 1). The resulting solid is removed by filtration and recrystallized from 180 ml. of water yield, about 3 g. It may be purified by steam distillation, affording colorless crystals m. p., 120-122°. 

Among the problems confronting organic chemists, two especially seemed to test the limits of the classical structure theories, namely, benzene and acetoacetic ester, also known as ethyl acetoacetate. Arthur Lachman, a Munich-... 

Ochiai and Ito reported that the reaction of ethyl acetoacetate and diethyl aminomethylenemalonate (13) in the presence of hydrogen chloride gave 4-hydroxypyridine-3-carboxylate (1314) at room temperature, while in the presence of sodium in boiling benzene, the product was 2-methyl-4-hydroxypyridine-3,5-dicarboxylate (1315) (41CB1111). Aqui et al. proved... 

A MiXTbire of 12 g. (0.50 gram atom) of magnesium turnings, 130 g. (1.0 mole) of ethyl acetoacetate, 200 g. of benzene (dried over sodium), and 120 g. (1.50 moles) of acetyl chloride is heated under reflux for two hours in a i-l. round-bottomed flask provided with a condenser closed by a calcium chloride tube and supported in an oil bath (85-90°) (Note 1). The yellow reaction mixture is cooled in an ice bath, and the liquid portion decanted into a separatory funnel. The residue in the flask is washed twice with 50-cc. portions of ether, and the ethereal solution poured over ice. The ether-water mixture is then added to the benzene solution in the separatory funnel, and the mixture is shaken thoroughly (Note 2) the aqueous layer is drawn off and discarded. The benzene-ether solution is washed once with 500 cc. of 5 per cent sodium bicarbonate solution, once with 50 cc. of water, and finally dried over calcium chloride. The ether and most of the benzene are removed by distillation from a water bath, and the remainder of the benzene is driven off at 50°/5o mm. The ethyl diacetylacetate is then precipitated from the residue as copper derivative by the addition of 1200 cc. of a saturated aqueous solution of copper acetate (Note 3). After addition of the copper acetate solution, the contents of the flask are shaken vigorously now and then and allowed to stand for an hour to ensure complete precipitation of the copper derivative. The blue copper derivative is filtered on a Buchner funnel, washed with two 50-cc. portions of water, and transferred directly to a separatory funnel where it is mixed with 600 cc. of ether. 

The reaction of ethyl acetoacetate with malonyl dichlorides has been used to synthesize a range of substituted 4-hydroxypyran-2-ones (58CB2849). Yields and purity of the products were best using benzene as solvent either without a catalyst or using magnesium acetate in this role. Hydrolysis of the C-5 ester function and subsequent decarboxylation are both feasible. 

A. Ethyl fi-Pyrrolidinocrotonate. Ethyl acetoacetate (130 g., 1.0 mole) (Note 1) and pyrrolidine (71 g., l.Omole) are dissolved in 400 ml. of benzene and placed in a 1-1. one-necked flask fitted with a Dean-Stark water separator on top of which is a condenser fitted with a nitrogen inlet tube. The reaction mixture is placed under a nitrogen atmosphere (Note 2) and then it is brought to and maintained at a vigorous reflux for 45 minutes, at which time the theoretical amount of water (18 ml.) has been collected. The benzene is then removed with a rotary evaporator. The residual ethyl /9-pyrrolidinocrotonate is highly pure and may be used without distillation (Note 3) yield 180 g. (98%). 

Procedure for 1,3-dioxolane formation with ethyl acetoacetate by azeotropic removal of water.128a Ethyl acetoacetate (30 g, 0.23 mol), ethane-1,2-diol (16g, 0.248 mol), a crystal of toluene-p-sulphonic acid and benzene (50 ml) (CAUTION) were placed in a round-bottomed flask fitted with a Dean and Stark water separator (Fig. 2.31(a)) and a reflux condenser. The reaction mixture was heated until no more water collected. The product was fractionally distilled under reduced pressure to give the cyclic acetal (35 g, 87%), b.p. 99.5-101 °C/17-18 mmHg. 

A mixture of 560 g of potassium carbonate, 700 ml of ethanol (96%), 404 g of 1,3-dibromopropane and 260 g of ethyl acetoacetate was heated with stirring to go 60°C. After the reaction had subsided, the reaction mixture was refluxed for 5 hours. Then the bulk of the alcohol was distilled off under ordinary pressure and the residue was mixed with 1.5 L of water. The resulting oily layer was separated, and the aqueous phase was extracted with benzene and the benzene layer was combined with the oil. After drying with sodium sulfate the benzene was distilled off and the residue was fractionally distilled 250 g (73% of theory) of 2-methyl-3-carbethoxy-5,6-dihydropyrane of boiling point 105°-108°C were obtained. 

B Graft copolymer recovered by pouring the dilute benzene solution into n-hexane. D Dispersed, ND Not dispersed. a Mn= 1.14 x10s. d Ethyl acetoacetate. 

Esterification of amino acids. The amino group of an amino acid can be protected as the enamine 1, formed by reaction with ethyl acetoacetate and a base in benzene/ DMSO. After alkylation the protective group is removed by addition of an acid, particularly TsOH, to provide amino acid ester salts (equation I). 

Keto esters. When ethyl acetoacetate (1) is heated with a nitrile in benzene or chlorobenzene in the presence of stannic chloride a tin(IV) complex (2) is formed. When 2 is hydrolyzed by acid, the acyl group is cleaved preferentially to give a new i3-keto ester (3). 

The aluminum derivative of ethyl acetoacetate is a white crystalHne material, reported to melt at 76°, or 78 to 79°. It supercools readily from the melt to a straw-colored, very viscous liquid. Molecular weight determinations in carbon disulfide indicate that the compound is not associated in that solvent. The aluminmn derivative of ethyl acetoacetate is very soluble in benzene, ether, and carbon disulfide. It is less soluble in petroleum ether or cyclohexane and is insoluble in water. The compound boils at 190 to 200° at 11 mm. The reported dipole moment, in benzene, is 3.96 Debye. Surface tension and density values for the liquid above the melting point have been reported by Robinson and Peak. ... 

Liquid phase modifications. Alternatively a porous membrane can be reduced in pore size by a liquid deposition prcx ess where the membrane is dipped into a solution or sol to form deposits inside the membrane pores. For example, a silicon nitride tube with a mean pore diameter of 0.35 pm is first immersed in a solution of aluminum alcoholate (aluminum isopropylate or 2aluminum tris(ethyl acetoacetate) or ethyl acetoacetate aluminum diisopropylate) in an organic solvent (hexane, cyclohexane, benzene, isopropanol, etc.). It is then treated with saturated water vapor to hydrolyze the alcoholate or chelate to form bochmite inside the pores, thus changing the pore diameter to as small as 20 nm [Mitsubishi Heavy Ind., 1984a and 1934b]. Upon calcining at 800X, boehmite transforms into transition-alumina. 

C6H3CIN204 1 -chloro-2,4-dinitrobenzene 97-00-7 in benzene 3.238 1 7881 C6H10O3 ethyl acetoacetate 141-97-9 gas 2.960 1... 

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