Ethylformate

The reaction of phosphorus pentasulfide with a-acylamino carbonyl compounds of type Ilia also yields thiazoles. Even more commonly, a mercaptoketone is condensed with a nitrile of type IVa or a-mercaptoacids or their esters with Schiff bases. This ring closure is limited to the thiazolidines. In the Va ring-closure type, /3-mercaptoalkylamines serve as the principal starting materials, and ethylformate is the reactant that supplies the carbon at the 2-position of the ring. These syntheses constitute the most important route for the preparation of many thiazolidines and 2-thiazohnes. In the Vb t3fpe of synthesis, one of the reactant supplies only the carbon at the 5-position of the resultant thiazole. Then in these latter years new modern synthetic methods of thiazole ring have been developed (see Section 7 also Refs. 515, 758, 807, 812, 822). 

Substituted 5-hydroxythiazoles (267b), Rj = alkylmercapto, acyl-amino, and sec-amino, are prepared by cydization of N-thioacyl-amino acids (266) with phosphorus tribromide or acetic anhydride (Scheme 137) (317, 350). i en the cydization of 266, R2 = H, is carried out with acetic anhydride in the presence of benzaldehyde (317, 325) or ethylformate (317), the benzylidene (268), R2=Ph, Rj = SR or CH2Ph, or 4-ethoxymethylene (268), Rj = SR and R2 = OEt, derivative is obtained directly (Scheme 138). 

The mechanism of the Hurd-Mori reaction has been discussed extensively in the review by Stanetty. The mechanism of the reaction was initially postulated by Hurd-Mori based on the isolation of intermediate 10. This intermediate was shown to transform into the desired thiadiazole upon heating in ethanol, either with or without acid. The reaction was thought to proceed via the four-membered intermediate 11, which would release the volatile ethylformate as a by-product. In 1995, Kobori and co-workers were able to isolate and determine crystallographically a very similar intermediate structure to 10 in their mechanistic studies of the reaction. ... 

When only one carbonyl is present, ethylformate can be used as an activating auxiliary ... 

Synonyms Methylacetic acid ethylformic acid ethanecarboxylic acid propanoic acid... 

Stanozol Stanozol, 17a-methyl-5a-androstano[3,2-c]pyrazol-17j3-ol (29.3.13), is made by reducing the double bond at C4-C5 in methyltestosterone, which has independent interest as an anabolic drug of mestanolone (29.3.11). Mestanolone undergoes formylation with ethylformate in the presence of sodium ethoxide, forming a 2-formyl (oxymethylene) derivative (29.3.12), which upon reaction with hydrazine easily cyclizes to the desired stanazole (29.3.13), which is a pyrazol-condensed steroid system [33,34]. 

Fluorouracil Fluorouracil, 4-fluorouracil (30.1.3.3), is made by condensing the ethyl ester of fluoroacetic acid with ethylformate in the presence of potassium ethoxide, forming hydroxy-methylenfluoroacetic ester (30.3.1), which cyclizes by reacting it with S-methyl-isothiourea to 2-methylthio-4-hydroxy-5-fluoropyrimidine, which is subsequently hydrolyzed by hydrochloric acid to fluorouracil (30.1.3.3) [21,22]. An alternative method of synthesizing... 

A detailed description of the prepn of 4 amino-y-sym-triazole by heating formylhydra-zine at 150—200° is given in Ref 3 Formyl-hydrazine was obtained by heating a mixt of ethylformate and hydrazine hydrate in ale fat 18 hours. In Refs 4 5 is described a method of prepn of this a min otri azole starting with the treatment of hydrazine hydrate and carbon monoxide at high pressure and elevated temps... 

In spite of the fact that this chromatographic technique is not generally associated with carbohydrate analysis, some applications are found in the literature where silica gel has been employed either directly or indirectly (after modification of the phase or the analytes). The use of silica gel for this purpose involves a polar eluent such as ethylformate/EtOH/H20 (6 2 1, v/v/v) and has been applied to the chromatographic separation of some mono- and disaccharides. 

Ethylformal Polysulfide (LP—33). Used, under the code name Unit No 533,as fuel in some rocket propellants Ref ProplntManual SPIA/M2 (1962)... 

ETHYLFORMIC ACID KYSELINA PROPIONOVA LUPROSIL METACETONIC ACID METHYL ACETIC ACID PROPANOIC ACID PROPIONIC ACID (ACGIH,DOT,OSHA) PROPIONIC ACID GRAIN PRESERVER PROZOIN PSEUDOACETIC ACID SENTRY GRAIN PRESERVER TENOX P GRAIN PRESERVATIVE... 

D. Williams and W. Gordy. J. Am. Chem. Soc. 59, 817-20 (1937). IR frequency and intensity changes, methanol in ethyl-acetate, ethylformate. 

Carboxyethane ethanecarboxylic acid E280 ethylformic acid metacetonic acid methylacetic acid propanoic acid pseudo-acetic acid. 

E281 ethylformic acid, sodium salt, hydrate methylacetic acid, sodium salt, hydrate sodium propanoate hydrate sodium propionate hydrate. 

Synonyms Ethanecarboxylic acid Ethylformic acid Carboxyethane Methylacetic acid Chemical/Pharmaceutical/Other Class Antifungal... 

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