Diazoacetic acid

Supplement XXV, 2nd 1936 3458-3793 Hydroxy-indanthrene, 102. Carboxylic acids Diazoacetic acid, 109. 

Furan and thiophene undergo addition reactions with carbenes. Thus cyclopropane derivatives are obtained from these heterocycles on copper(I) bromide-catalyzed reaction with diazomethane and light-promoted reaction with diazoacetic acid ester (Scheme 41). The copper-catalyzed reaction of pyrrole with diazoacetic acid ester, however, gives a 2-substituted product (Scheme 42). 

Azido-. azido- (sometimes) acido-. -essig saure,/. azidoacetic acid (diazoacetic acid). azidoUtisch, a. acidolytic. 

Diazo-benzol, n. diazobenzene, -essigsaure,/. diazoacetic acid, -kdrper, m. diazo compound. -Idsung, /. diazo solution, -salz, n. diazo salt (usually a diazonium salt), -schwarz, n, diazo black, diazotierbar, a. diazotizable. diazotieren, v.t. diazotize. 

Ketones react with esters of diazoacetic acid in the presence of Lewis acids such as BF3 and SbCl5.82... 

Trimethyllead diazoacetic acid ethyl ester reacts with activated alkenes or acetylenes to provide organolead pyrazoles or pyrazolines197 ... 

The diazoacetic acid ethyl ester is prepared by the following reaction... 

Hydrazine was first obtained by hydrolytic decomposition of bis-diazoacetic acid . The latter, a tetrazine derivative, is obtained from ethyl diazoacetate in the form of alkali salt by the (catalytic) action of strong alkali. Two molecules of the acid simply unite and, at the same time, the ester group is hydrolysed ... 

Other methods for the preparation of diazoacetic acid esters... 

AIkynyl(diisopropylsilyl)oxy-diazoacetates (295) undergo intramolecular 1,3-dipolar cycloaddition in good yield when R = H (isolation of silver pyrazolide 296 was possible) and R, R = Me,Me or (CH2)s, but no reaction occurred when R = H, R = H or R =Me (340). The silicon substimtion is apparently crucial. Replacement of the Si(i-Pr)2 in 295 (R = R = H) by Si(f-Bu)2 allowed an uncatalyzed intramolecular [3 + 2] cycloaddition to take place [xylene, 140-160 °C, 11% yield (340)], while Ag(I) catalysis led to decomposition. A diazoacetic acid (2-propyn-l-yl)oxysilyl ester also produced a bicyclic pyrazole, but in low yield. On the other hand, the same diazo compound 295, which reacted intm-molecularly under silver ion catalysis, underwent dimerization by an /nfermolecular... 

The best known example of the treatment of a primary aliphatic amine with nitrous acid involves the reaction of esters of glycine hydrochloride with sodium nitrite to form esters of diazoacetic acid. This reaction is carried out at low temperatures and under such reaction conditions that any IV-nitroso primary amine which might have been formed is immediately converted to the diazoacetate [15, 16]. Treatment of 1-methyl-2,2,2-trifluoroethylamine hydrochloride, another primary amine, with sodium nitrite in an aqueous system also evidently leads to the corresponding diazoalkane [17]. 

Mono- and bis(trimethylsilyl)-substituted cyclopropanones 15 are stable enough to be isolated. Reaction with diazomethane,131 trimethylsilyldiazomethane131 and diazoacetic acid es-ters 130 131 yielded mono-, bis- and tris(trimethylsilyl)-subslitutcd cyclobutanones 16 and 17. In all cases, the regio- and stereochemistry arc in accord with the general rules given. 

Diazoacetic Acid, Methyl Ester or Methyldiazo-acetate (called Diazoessigsaure-methylester in Ger), N2CH.CO2.CH3 mw 100.08, N 27.99% It-yel expl liq, bp 31° at 12mm Hg distillation, even under reduced pressure, is extremely dangerous, since heat causes the compd to detonate violently d 1,158 at 25°, nQ 1.4515 1,4676 at 20.6° was... 

Diazoacetic acid, ethyl ester 5 D1155—D1156... 

When hydrazine hydrate is neutralised with sulphuric acid, dihydrazine sulphate, (N2H4)2.I-I2S04, is obtained.8 Hydrazine sulphate, N2H4.H2S04, is obtained when iis-diazoacetic acid, C2TI2N4(COOII)2, is warmed with sulphuric acid 9... 

Diazomethane Di-t-butyl- Diazoacetic acid Diazomalonic Diphenyl-... 

Fig. 14.23. Ring expansion of a cyclohexanone via addition of diazoacetic acid ethyl ester and subsequent [l,2]-rear-rangement.

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