DIAZO-, ETHYL ESTER

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

Ethyl diazoacetoacetate Acetoacetic acid, 2-diazo-, ethyl ester (8) Butanoic acid, 2-dlazo-3-oxo-, ethyl ester (9) (2009-97-4)... 

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) ... 

The simple primary amines of the aliphatic series, then, do not form diazo-compounds because the reaction which would le, d to their formation only occurs at a temperature at which they are destroyed. The reactivity of the NH2-group can, however, be increased by a neighbouring carbonyl group. Thus we come to the case of the esters of the a-amino-carboxylic acids and of the a-amino-ketones. The ethyl ester of glycine can be diazotised even in the cold the diazo-compound which does not decompose under these conditions undergoes stabilisation by elimination of water and change into ethyl diazoacetate ... 

Wahrend Diazo-diphenyl-methan mit Benzofurazan-l-oxid am heterocyclischen Ringreagiert (s.S.803), bildet 5-Nitro-benzofurazan-l-oxid mit Diazo-essigsaure-methylester bzw. -ethyl-ester 8-Ethoxycarbonyl- bzw. 8-Melhoxy-carbonyl-6H-[Pg.805]

CuH12N504 mw 278.28 N 25.17% OB to C02 —137.99% pale yel silvery flakes (from aq alc) mp, expldsca 130°. Sol inaq ethanol. Prepn is by treating 3.5-diazo-6.6-dimethyl-hexahydro-l,2,4-triazine with a soln of m-nitrobenzenediazonium chloride. The triazine also forms an expl Potassium Salt bright ver-milHon colored ndles expl decompn ca 166° obtd by treating a-ureido-a-m-nitrophenylene diazoamino-i-butyric acid ethyl ester with K ethylate sol in ethanol Refs 1) Beil 26, 222 2) J.R. Bailey L. 

Essigsaure Diazo-phenyl- -ethyl-ester X/4, 563 El4b, 1146 (aus Hydrazon)... 

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... 

Acid proteases are inactivated by active-site specific reagents, diazoacetylnorleucine ethyl ester and other diazo compounds, and epoxy (p-nitrophenoxy)propane. Covalently labelled aspartic acid peptides have been isolated from pepsin, chymosin (= rennin), and penicillopepsin. The peptides labelled with the diazo compounds have similar sequences and differ from the epoxy (p-nitrophenoxy)pro-pane labelled peptides. These results indicate two aspartic acids at the active site and suggest homology between the enzymes. The latter is confirmed by a comparison of the sequence data. Studies of the action of porcine pepsin and penicillopepsin on some dipeptides with free N-terminal groups show transpeptidation involving a covalent acyl intermediate. It is proposed that there are differences in the mechanism of action of pepsin which are determined by the nature of the substrate. 

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. 

A study of Rh2Ln4-catalyzed decomposition of 2-diazo-A-phenylmalo-namic acid ethyl ester 128 (R = C02Et) showed, that with perfluorocarbox-amides as catalyst ligands, the aromatic C—H insertion giving rise to oxindoles 129 occurs in preference to aliphatic C—H insertion, addition to C=C and C=C bonds, O—H insertion, and ylide formation, all of which are observed simply by switching to a carboxylate-based rhodium catalyst (94JOC2447). 

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