Acetic acid, Diazo

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

Copper(ll) acetylacetonate Copper, bis(2,4-pentanedionato-0,0 )- (9) (46369-53-3) Methyl diazoacetate Acetic acid, diazo-, methyl ester (8,9) (6832-16-2) Triethylammonium fluoride Triethylamine hydrofluoride (8) Elhanamine, N,N-diethyl-, hydrofluoride (9) (29585-72-6)... 

Acetic acid, reaction with bicyclo[2.2.1]-hepta-2,S-diene, 46, 74 reaction with dibenzyl ketone, 47, S4 Acetic acid, diazo-, ferf-BUTVL ester, 48,36... 

Required Aniline hydrochloride, 4 g. aniiinc, 16 ml. diazo aminobenzene, 8 g. acetic acid, 20 ml. 

Add, with stirring, a solution of 6 8 g. of the fiis-diazo ketone in 100 ml. of warm dioxan to a suspension of 7 0 g. of freshly precipitated silver oxide in 250 ml. of water containing 11 g. of sodium thiosulphate at 75°. A brisk evolution of nitrogen occurs after 1 5 hours at 75°, filter the liquid from the black silver residue. Acidify the almost colourless filtrate with nitric acid and extract the gelatinous precipitate with ether. Evaporate the dried ethereal extract the residue of crude decane-1 10-dicarboxylic acid weighs 4 -5 g. and melts at 116-117°. RecrystaUisation from 20 per cent, aqueous acetic acid raises the m.p. to 127-128°. 

Alternatively, treat a solution of 3 9 g. of the 6is-diazo ketone in 50 ml. of warm dioxan with 15 ml. of 20 per cent, aqueous ammonia and 3 ml. of 10 per cent, aqueous silver nitrate under reflux in a 250 or 500 ml. flask on a water bath. Nitrogen is gently evolved for a few minutes, followed by a violent reaction and the production of a dark brown and opaque mixture. Continue the heating for 30 minutes on the water bath and filter hot the diamide of decane-1 lO dicarboxyhc acid is deposited on cooling. Filter this off and dry the yield is 3 -1 g., m.p. 182-184°, raised to 184-185° after recrystallisation from 25 per cent, aqueous acetic add. Hydrolyse the diamide (1 mol) by refluxing for 2-5 hours with 3N potassium hydroxide (4 mols) acidify and recrystaUise the acid from 20 per cent, acetic acid. The yield of decane-1 10-dicarboxyhc acid, m.p. 127-128°, is almost quantitative. 

Thermal conversion of diazirines to linear diazo compounds was postulated occasionally and proved by indirect methods. The existence of a diazo compound isomeric to diazirine (197) was proved spectroscopically on short thermolysis in DMSO (76JA6416). An intermediate diazoalkane was trapped by reaction with acetic acid, yielding the ester (198) (77JCS(P2)1214). 

The ionization of (E)-diazo methyl ethers is catalyzed by the general acid mechanism, as shown by Broxton and Stray (1980, 1982) using acetic acid and six other aliphatic and aromatic carboxylic acids. The observation of general acid catalysis is evidence that proton transfer occurs in the rate-determining part of the reaction (Scheme 6-5). The Bronsted a value is 0.32, which indicates that in the transition state the proton is still closer to the carboxylic acid than to the oxygen atom of the methanol to be formed. If the benzene ring of the diazo ether (Ar in Scheme 6-5) contains a carboxy group in the 2-position, intramolecular acid catalysis is observed (Broxton and McLeish, 1983). 

The Pd°-catalyzed arylations using arenediazonium tetrafluoroborates are limited to those diazonium salts that can be manipulated at room temperature. The reaction can, if necessary, be performed at temperatures up to 50 °C by using a mixture of an arylamine and tert-butyl nitrite in chloroacetic acid or in a mixture of chloroacetic and acetic acid (Kikukawa et al., 1981a). Styrene reacted with fourteen arylamines in the presence of 5 mol-% Pd(dba)2 to give the corresponding substituted stilbenes in yields of 46-97%. It is important for good yields to carry out these reactions in an acidic system. Without acid the yield was low (11%), and diazo tars were also formed. 

Protoadamantanone has been prepared by the nitrous acid deamination of 2-amino-l-adamantanol (77%), by aprotic diazo-tization of endo-7-aminomethylbicyclo[3.3.1]nonan-3-one in benzene with an equivalent amount of acetic acid (67%), and by thermolysis of 1-adamantyl hypohalites followed by base-promoted cyclization of the resulting halo ketones (32-37%)." In spite of low and erratic yields, the last reaction sequence has provided the most convenient route to the protoadamantanes, since the other two approaches require lengthy syntheses of the starting materials. 

Azidation.1 Arylsulfonyl azides generally react with enolates to effect net diazo transfer, but this hindered and electron-rich azide can effect azide transfer at the expense of diazo transfer. The nature of the enolate counterion also plays a role, with K being more effective than Na. In addition, acetic acid (or KOAc) is required as the quench for decomposition of the triazine intermediate to the azide with elimination of the arylsulfinic acid, ArS(0)0H. By use of these conditions, chiral N-acyloxazolidones such as 2 undergo diastereoselective azidation to give the azides 3 in 75-90% yield and in high optical purity (>91 9). These... 

The nitration of 2-amino-4,6-dinitrotoluene (63) with a mixtnre of nitric acid in sulfuric and acetic acids yields 2-diazo-3-methyl-4,6-dinitrophenol (65) in 75 % yield without isolation of the intermediate nitramine (64)." ... 

The nitration of both 4-methyl- and 4-chloro-2,6-dinitrotoluenes (66 and 67) with mixed acid in acetic acid at subambient temperature allows the isolation of the nitramines, (68) and (69), respectively. Thermolysis of (68) and (69) in refluxing methylene chloride yields the corresponding diazophenols, (70) and (71), respectively. Scilly and co-workers isolated 2-diazo-4,6-dinitrophenol (DINOL) (53) from the thermolysis of fV,2,3,5-tetranitroaniline (73) in ethyl acetate at 60 °C. 

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