Acetic acid, diazo-, ethyl ester

ETHYL DIAZOACETATE (Acetic acid, diazo-, ethyl ester)... 

C2-homologizati on of sugars with, 264-265 Acetamide, JV-bromo- (AcNHBr, NBA) bromohydrination with, 275-276, 287 Acetaminophen (= paracetamol), 301 Acetate, piperidinium cat. for aldol add., 82 —, sodium a-epimerization of ketones, 277 opening of oxiranes, 282 Acetic acid, anhydride (AcfO) protection with. See Protection Pummerer rearr. with, 51, 265 —, esters (See also Protection of hydroxy groups) C-H acidity, 10 1-methylethenyi ester pr., 174 transenolization, 58 —, bromo-, esters pr., 179 a2-synthon, 19, 65, 309 d2-synthon, 19, 301 —, chloro-, esters pr., 179 hydantoins from, 308 —, cyano-, esters pr., 177 pyrrolines from, 298 —, (dialkoxyphosphinyl)-, esters pr 188 Wittig-Horner olefinations, 267, 282 —, diazo-, ethyl ester pr, 176, 178 cyclopropanes from, 74—75 —, dichloro- deblocking of pixyl ethers, 342 —, hydroxy-, esters pr., 176 —, hydroxyphenyl-, (S)- (l-mandelic acid) ... 

DIAZOACETATE (ESTER) SERINE see ASA500 DIAZO-ACETIC ACID ESTER with SERINE see ASA500 DIAZOACETIC ACID, ETHYL ESTER see DCN800 DIAZOACETIC ESTER see DCN800 N-DIAZOACETILGLICINA-IDRAZIDE (ITALIAN) see DC0800... 

Diazo-acetic Esters. —Mercuric oxide dissolves in the cooled ethyl ester of diazo-acetic acid, and the product is extracted with ether. From the ethereal solution yellow, rhombic crystals of mercury bis-diazo-aceiic ethyl ester are deposited, the parameters of which are a b c=0-4546 1 0-72527. The crystals melt with decomposition at 104° C., and are affected by direct sunlight, mercury separating out. The substance explodes on concussion and is volatile in steam, with some decomposition. 

Aliphatic Diazo Compounds.—It has been stated that primary aliphatic amines do not yield diazonium compounds when treated with nitrous acid. It is of interest to note, however, in connection with the aromatic diazo compounds, that certain derivatives of the ahphatic amines yield compounds when treated with nitrous acid which resemble somewhat in their reactions the diazonium compounds. When the ethyl ester of amino-acetic acid is treated with nitrous acid a yellow oil is obtained, which explodes when heated. The reaction takes place according to the equation,—... 

The catalytic activity of rhodium diacetate compounds in the decomposition of diazo compounds was discovered by Teyssie in 1973 [12] for a reaction of ethyl diazoacetate with water, alcohols, and weak acids to give the carbene inserted alcohol, ether, or ester product. This was soon followed by cyclopropanation. Rhodium(II) acetates form stable dimeric complexes containing four bridging carboxylates and a rhodium-rhodium bond (Figure 17.8). 

Although the present procedure illustrates the formation of the diazoacetic ester without isolation of the intermediate ester of glyoxylic acid />-toluenesulfonylhydrazone, the two geometric isomers of this hydrazone can be isolated if only one molar equivalent of triethylamine is used in the reaction of the acid chloride with the alcohol. The extremely mild conditions required for the further conversion of these hydrazones to the diazo esters should be noted. Other methods for decomposing arylsulfonyl-hydrazones to form diazocarbonyl compounds have included aqueous sodium hydroxide, sodium hydride in dimethoxyethane at 60°, and aluminum oxide in methylene chloride or ethyl acetate." Although the latter method competes in mildness and convenience with the procedure described here, it was found not to be applicable to the preparation of aliphatic diazoesters such as ethyl 2-diazopropionate. Hence the conditions used in the present procedure may offer a useful complement to the last-mentioned method when the appropriate arylsulfonylhydrazone is available. 

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