Aceto-acetic esters

Winch, if any, of the following compounds can be prepared by an aceto-acetic ester synthesis Explain. 

The preparation of dithianes from enamines by reaction with trimethylene dithiotosylate (propane-1,3-dithiol di-p-toluenesulfonate) has been applied with enamines derived from oholostan 3 one, aceto-acetic ester, and phenylacetone.6 7 Reactions of trimethylene dithiotosylate with hydroxymethylene derivatives of ketones also give rise to dithianes thus the hydroxymethylene derivative of cholest-4-en-3-one can be converted to 2,2-(trimethylenedithio)cholest-4-en-3-one. 1,3-Dithiolanes are obtained in a similar manner by reaction of ethylene dithiotosylate1 with the appropriately activated substrate.5,7... 

For such cases in which the two forms have been brought to light solely as a result of improved experimental methods, the term tauto-merism " has been modified to desmotropism In desmotropic substances the tautomeric relations are therefore particularly clear and well defined numerous examples have become known, which now also include aceto-acetic ester. The case of acetylacetone is quite similar, but here the formation of the enol-form is much more favoured. The liquid substance contains up to 80 per cent of enol. 

Acetyluracil — Ethyl 2-hydroxy-4-methyl-5-pyrimidinecarboxylate (XXXVI), which is prepared by the cyclization of the ureidomethylene derivative of aceto-acetic ester, can be caused to rearrange into 5-acetyluracil (XXXVII) in dilute alkali [304]. Compound (XXXVII) can also be prepared from diketene and ethyl carbamate, followed by treatment with ethyl orthoformate and cyclization with ammonia [305]. 

This reaction is very general and other substituted aceto-acetic esters may be obtained in approximately the same yields if this procedure is followed. 

A broad spectrum of hydrogen-containing nucleophiles react with both aromatic and aliphatic isocyanates compounds containing OH groups (H20, alcohols, phenols, oximes, acids), SH groups (H2S, mercaptans), NH groups (NH3, amines, hydrazines, amides, ureas, urethanes), enolizable compounds such as malonic and aceto acetic esters, etc. Some reactions are given in Table 2.5. 

Geuther represented the substance as CHg.C OH) CH.COOC2H6, that is /3-hydroxycrotonic ester, but Frankland and Duppa preferred the keto formula CH8.CO.CH2.COOC2H6, and represented it as aceto-acetic ester,7... 

These substituted esters, like aceto-acetic ester itself, can be hydrolysed in two different ways and thus yield a variety of ketones aud acids of the acetic series.14... 

The monosodium derivative of aceto-acetic ester on treatment with iodine undergoes condensation to a dibasic ester (diaceto-succinic ester). 

Acetyl aceto-acetic ester is prepared by the action of acetyl chloride upon the compound CH3.CO.CH Na.COOC2H5, and on hydrolysis gives acetic and aceto-acetic acids ... 

Aceto-acetic ester is technically valuable in the preparation of antipyrine. The ester is first allowed to react with phenyl-liydrazine, and the ring compound formed is then converted into autipyrin by methyl iodide and sodium ... 

By substituting aceto-acetic ester for acetaldehyde, a quinoline derivative is obtained ... 

A mixture of aceto-acetic ester (33 gms.) with sodium (5 gms.) dissolved in alcohol (70 gms.) is treated with mono-chlor-acetic oster (32 gms.) which is added gradually. The mixturo is then boiled on the water-bath until no alkaline reaction is shown (about two hours), after which it is treated, with water to dissolve sodinm chloride, extracted with ether, and the ethereal extract dried over calcium chloride and distilled. Yield 12—15 gms. of a pale yellow oil, b.p. 256°. 

Minnuni308- 367 observed that, in the presence of anhydrous zinc chloride, phenylhydrazones of aromatic aldehydes react with aceto-acetic ester and its analogs to form derivatives of jS-aminocrotonic ester, which on cyclization and dehydrogenation give the corresponding pyrazoles. 

Many similar examples of the application of the Bronsted relation may be cited, including the mutarotation of glucose, the iodination of acetone, the bromination of aceto-acetic ester, and the dehydration of 1,1-dihy-droxyethane to acetaldehyde- and many other closely related compounds (see R. P. Bell, loc, cit). It is usually found that on going from one acid to another structurally very different, the two acids will not fit the same... 

Anhydrides—Continued reduction to alcohols, 155 reduction to lactones, 535 Arenes, see Hydrocarbons, aromatic Amdt-Eistert reaction, 433, 487, 573 Aryl esters. Fries rearrangement, 344 hydrolysis, 169 preparation, 169 Aryl halides, see Halides Atyloxy acids, preparation, by aceto-acetic ester synthesis, 430 by malonic ester synthesis, 429 from atyloxy alcohols, 419 from atyloxy cyanides, 414 preparations listed in table 48, 460 Aryloxy acyl halides, preparation, 547 preparations listed in table 61, 553 Aryloxy esters, preparations listed in table 55, 516... 

How would you prepare the following compounds using either an aceto-acetic ester synthesis or a malonic ester synthesis ... 

This reaction, however, yields a compound containing a hydroxyl group instead of a carbonyl group and the question is which is the true formula and which represents the constitution of aceto acetic ester The answer, strange as it may seem, is that both are right for we have reactions some of which prove one and some the other constitution. 

Aceto Acetic Ester S3mtheses.— These alkyl and acyl derivatives of ethyl aceto acetate, both the mono- and the di- derivatives, react now on hydrolysis in the two ways given above, i.e.y by Xheketonehydro-lysis or the acid hydrolysis and we may thus obtain a large number of ketones and acids as desired. 

Di-methyl aceto acetic ester Methyl iso-propyl ketone... 

Action of Hydrogen and of Ammonia.— Another reaction of aceto acetic ester should be mentioned. When hydrogen (sodium amalgam), ammonia or alkyl primary amines react with aceto acetic ester, crotonic acid (p. 173) CHs—CH = CH—COOH, or derivatives of it are obtained. The fact that crotonic acid contains a double bond seems to indicate the presence of a double bond in aceto acetic ester, and would be evidence for the enol form. 

From Aceto Acetic Ester.—The simplest di-ketone, which is naturally an fl//>/fd-di-ketone, is CH3—CO—CO—CH3, di-acetyl. It is made from methyl aceto acetic ester by an interesting reaction involving the ketone hydrolysis. When aceto acetic ester is treated in the hot with dilute alkali the ketone hydrolysis takes place. If, however, the treatment is in the cold, hydrolysis results simply in the formation of the potassium salt. 

From Ethyl Acetate.—The simplest member of this group is CH3— CO—CH2—CO—CH3 which is plainly acetyl acetone. It is best made by a reaction exactly analogous to the one used in preparing aceto acetic ester. In making the latter ethy 1 acetate is condensed with itself by means of sodium and ethyl alcohol (sodium ethylate) as described already (p. 254). If instead of condensing with another molecule of itself ethyl acetate condenses with acetone we obtain acetyl acetone, as follows ... 

In these reactions the characteristic property of malonic acid and its esters rests in the methylene group, (—CH2—). This same group we will recall is the reactive part of aceto acetic ester and we shall find that the linkage of the group is alike in the two compounds. When... 

From Aceto-acetic Ester.—Glutaric acid may also be made by either the aceto-acetic ester synthesis or by the malonic ester synthesis as follows,... 

Glutaric Anhydride.—These two syntheses show the wonderful adaptability of the aceto-acetic ester and the malonic ester syntheses in... 

Synthesis from Glycerol.--Citric acid is related to the two preceding acids and its constitution has been established by two syntheses, one from glycerol and the other from aceto-acetic ester. 

From Aceto-Acetic Ester.— The synthesis from aceto-acetic ester takes place according to the following scheme ... 

The constitution of the iso-dialuric acid was established by its synthesis from aceto-acetic ester and urea. 

S3mthesis of Collidine.—The most important synthesis of pyridine homologues is that of collidine from which pyridine may be obtained by elimination of the methyl groups by oxidation and loss of carbon dioxide. When aldehyde ammonia is heated with aceto-acetic ester a derivative of a di-hydrogenated collidine is obtained, as follows ... 

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