Acetoacetates ethyl ester

Preparation 75.—Ethyl Acetoacetate [Ethyl ester of i-on-butan add], CH3COCH2COOC2H5 and CH3C(OH) CH.COOC2H5. C6H10O3. 130. 

A rodenticide mainly effective against field rodents is crimidine (5), 2-chloro-4-dimethylamino-6-methylpyrimidine, which is prepared by chlorination of the condensation product of acetoacetic ethyl ester and urea, and subsequent reaction of the intermediate formed with dimethyl amine. The inactive isomer of the main product, 4-chloro-2-dimethylamino-6-methylpyrimidine, is formed in an amount... 

Chemical Designations - Synonyms Acetoecetic acid, ethyl ester, Acetoacetic ester Diacetic ether Chemical Formula CHjCOCH COOCjHj. 

A mixture of 4.98 g of acetoacetic acid N-benzyl-N-methylaminoethyl ester, 2.3 g of aminocrotonic acid methyl ester, and 3 g of m-nitrobenzaldehyde was stirred for 6 hours at 100°C in an oil bath. The reaction mixture was subjected to a silica gel column chromatography (diameter 4 cm and height 25 cm) and then eluted with a 20 1 mixture of chloroform and acetone. The effluent containing the subject product was concentrated and checked by thin layer chromatography. The powdery product thus obtained was dissolved in acetone and after adjusting the solution with an ethanol solution saturated with hydrogen chloride to pH 1 -2, the solution was concentrated to provide 2 g of 2,6-dimethyl-4-(3 -nitrophenyl)-1,4-dihydropyridlne-3,5-dicarboxylic acid 3-methylester-5- -(N-benzyl-N-methylamino)ethyl ester hydrochloride. The product thus obtained was then crystallized from an acetone mixture, melting point 136°Cto 140°C (decomposed). 

Acetoacetic acid N-benzyl-N-methyl-amino ethyl ester Nicardipine... 

Esters, like aldehydes and ketones, are weakly acidic. When an ester with an a- hydrogen is treated with 1 equivalent of a base such as sodium ethoxide, a reversible carbonyl condensation reaction occurs to yield a /3-keto ester. For example, ethyl acetate yields ethyl acetoacetate on base treatment. This reaction between two ester molecules is known as the Claisen condensation reaction. (We ll use ethyl esters, abbreviated "Et," for consistency, but other esters will also work.)... 

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. 

C2HjNa02, 127-09-3) see a-Acetyldigoxin Dextrothyroxine Fluazacort Fluprednidene acetate Pioglitazone Pyrrocaine sodium acetoacetic acid ethyl ester (C HyNaO, 19232-39-4) see Pentoxifylline sodium acetylide (Na(C2H))... 

A biomimetic synthesis of (-)-xestospongin A (116), (+)-araguspongine B (129), and (+)-xestospongin C (130) was developed (Scheme 12) [43], starting from a Weiler s alkylation of ethyl acetoacetate (131) with 1-bromo-4-chlorobutane (132) to give the ethyl ester of 8-chloro-3-oxooctanoate... 

Nicardipine Nicardipine, l,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-methyl-2-[(methyl-phenylmethyl)-amino]ethyl ester 3,5-pirididincarboxylic acid (19.3.7), is synthesized in a manner analogous to the synthesis of nifedipine, the only difference being that in the Hantsch synthesis, two different )3-dicarbonyl compounds are used simultaneously with o-nitrobenzaldehyde. During this, one of these in the enamine form of acetoacetic ester is simultaneously used as an amine component. A heterocycUzation reaction is accomplished by reacting, the methyl ester of 8-aminocrotonic acid with the 2-methyl-2-benzyl-aminoethyl ester of acetoacetic acid [24-27]. 

Knoevenagel adduct 239 of oxohomophthalimide 240 with malononitrile 27a in reactions with CH-acids behaves ambiguously (82CPB1215). Reactions of 239 with acetylacetone, ethyl esters of acetoacetic and ben-zoylacetic acids, as well as methyl pyruvate led to the formation of the desired spiropyrans 241. However, benzoylacetone, dibenzoylmethane, cyanacetamide, and oxindole always gave the same 242. Authors explain this feature in terms of a retro-cleavage of adducts of Michael product 239... 

Isodehydroacetic acid has been prepared by the action of sulfuric acid on acetoacetic ester 3 4 The ethyl ester has been prepared by the action of dry hydrogen chloride on acetoacetic ester 6 6 and by the sodium-catalyzed condensation of ethyl /3-chloroisocrotonate with ethyl acetoacetate3 The methyl ester of isodehydroacetic acid has been prepared by the thermal rearrangement of pyrazolines 7... 

Acetoacetic Acid, Ethyl Ester Acetoacetic Ester Acetone... 

ETHYL ACETOACETATE Acetoacetic Add,ethyl ester, Acetoacetic Ester, Diacetic Ether, EAA NL 2 2 0... 

The self-condensation of /3-keto esters and related compounds occurs under the influence of either acidic or basic catalysts and constitutes one of the earliest syntheses of pyran-2-ones (l883LA(222)l). It exemplifies a synthesis of type (ii) (Scheme 85). Ethyl acetoacetate, for instance, gives a mixture of 4,6-dimethyl-2-oxopyran-5-carboxylic acid and its ethyl ester other esters behave similarly (59RTC364). Decarboxylation of the pyrancarboxylic acid occurs at 160 °C in sulfuric acid. The formation of the pyranone proceeds through a 5-keto ester which is considered to result from attack of the enolic form of the ester on protonated ethyl acetoacetate (51JA3531). A detailed synthesis of the pyran-5-carboxylic acid is available <630SC(4)549). 

Acetic acid, (3,5,6-trichloro-2-pyridinyloxy)-as herbicide, 2, 513 Acetic formic anhydride chromone synthesis from, 3, 820 Acetoacetic acid ethyl ester... 

The typical / -keto ester is ethyl acetoacetate (ethyl 3-oxo-butanoate). A retro-synthetic disconnection on this compound points to one of the most common methods for its synthesis, namely the Claisen ester condensation. 

Microwave-assisted organic synthesis may also be used for carrying out the multicomponent reactions of ketones and 1,2-diamines [20, 21, 92, 100]. For example, the three-component reaction of o-PDA 1 with acetoacetic acid ethyl ester 83 and a series of aromatic and heteroaromatic aldehydes 84 proceeds under microwave irradiation with very high yields of diazepines 85 (up to 95%) [100]. Reaction of 2 equiv of cyclohexanone 86 with o-PDA 1 was also realized in a microwave field on a basic alumina surface in 4 min [92] (Scheme 4.27). 

To 1170 g ethyl acetoacetate at 100-110°C was added a little at time 1605 g bromosuccinimide. After cooling to the mixture was added 300 ml of carbon tetrachloride. From the mixture was isolated ethyl ester of bromoacetoacetic acid which was distilled at 105-125°C/18 mm yield 67%. 

YEAST REDUCTION OF ETHYL ACETOACETATE (S)-(+)-ETHYL 3-HYDR0XYBUTAN0ATE (Butanoic acid, 3-hydroxy-, ethyl ester, ( ))... 

Ethyl acetoacetate Acetoacetlc acid, ethyl ester (8) Butanoic acid, ethyl ester (9) (141-97-9)... 

The following example shows the self-condensation of ethyl acetate to give ethyl ace-toacetate (ethyl 3-oxobutanoate). Ethoxide is used as the base to avoid transesterification or hydrolysis of the ethyl ester (see Problem 22-34). The initial product is the enolate of ethyl acetoacetate, which is reprotonated in the final step. 

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