Similarity nitroacetate

Cklorodifluoronitrosomethane. ClCF2NO, mw 115.47 N 8.24% a dark blue liq or gas bp ca -35° (Refs 1, 2 6) CA Registry No 421-13-6 Preparation. It has been prepd by reactions analogous to those for prepn of trifluoronitrosomethane (Refs 2 5). It has also been prepd by the action of 33% aq nitric acid on chloro-difluorosulfenyl chloride (C1CF2SC1) (Ref 3), and by the action of hot coned HC1 on difluoro-nitroacetic acid (Ref 4). Its props and reactions are similar to trifluoronitrosomethane Refs 1) Beil 1, <99) 2) R.N. Hazeldine, JCS... 

Thus, the reaction of alkyl halides and a-halo esters with sodium nitrite provides a very useful synthetic method for nitroalkanes and a-nitro esters. However, ethyl bromoacetate is exceptional in that it fails to give ethyl nitroacetate on treatment with sodium nitrite.93 This is due to the acidic hydrogen of the ethyl nitroacetate, which undergoes a further reaction with sodium nitrite to give the oxidized products (see Section 6.1, which discusses the Nef reaction). In a similar way, the reaction of benzyl bromide with sodium nitrite at 25 °C gives benzoic acid predominantly. To get phenylnitromethane, the reaction must be carried out at low temperature (-16 °C) (Eq. 2.48).93... 

Primary nitro ketones, ethyl nitroacetate, and (phenylsulfony l)nitromethane react with alkenes in the presence of Lewis acids to give nitrile oxide cycloaddition.61a Similarly, the reaction of a-nitro ketones with TeCl4 generates the corresponding nitrile oxides, as shown in Eq. 6.36.61b... 

The nitroaldol reaction of methyl nitroacetate (199, Scheme 38) with 1,2 3,4-di-0-isopropylidene-a-D-ga/acfo-hexodialdo-l,5-pyranose (200) and 2,3-O-isopropyli-dene-D-glyceraldehyde (202) catalyzed by silica gel proceeded in almost quantitative yield, with high selectivity for attack on the aldehyde carbonyl group, giving derivatives 201 and 203, respectively. Two of the four possible diastereomers were detected as main products, and were obtained as a mixture. For the nitroaldol reaction with 200 gave similar results in either the presence or absence of silica gel, whereas the reaction with 202 did not proceed in its absence, showing that catalytic action of silica is mandatory in this case.176... 

A similar process can be performed with the use of cerium ammonium nitrate (CAN) for generation of radicals from another CH acid, viz., methyl nitroacetate (72b) (Scheme 3.22, Eq. 2). 

The main starting compound is the labeled nitroguanidine 257 obtained from guanidine with isotope-labeled potassium nitrate. Reduction of 257 to hydrazine carboximidamide 258 was carried out with zinc and, then, ring closure to 3-amino[l,2,4]triazole 259 was carried out using formic acid. Finally, the ring closure to form the [l,2,4]triazine ring - similar to other procedures presented in Scheme 54 - was perfected by reaction with nitrous acid followed by treatment with ethyl nitroacetate to 260. 

A similar base-induced rearrangement has been reported to occur at room temperature with the Z-isomer of 3-methyl-4-benzoylfuroxan oxime (143), yielding the 3-(a-nitroethyl)-4-phenylfurazan (144) (82G181), and with 3,4-diformaldoxime furoxan (145), which gives 3-(a-nitroacetal-doxime)furazan (146) (Scheme IV.57) (81AHC(2G)251). 

Similarly, o-phthalaldehyde is cyclized by ethyl nitroacetate to give 2-nitro-2-ethoxycarbonyl-indane-l,3-diol (86) in 71% yield, which can be hydrogenated to the corresponding amino acid (87)... 

A series of 4-hydroxy-3-nitro-2-quinolones (93 X = CH) has been synthesized from nitroacetic ester and isatoic anhydrides in the presence of sodium hydride [Eq. (29)].85 A similar reaction has produced the naph-thyridine derivatives 93 (X = N, R2 = H).86... 

Similar 2-hydroxy-3-nitro-l,8-naphthyridines (94) have been prepared by condensation of 2-aminonicotinaldehydes with nitroacetic ester in the presence of piperidine [Eq. (30)].87... 

Yet another variant which has found some use features /3-nitroacetate precursors <1999JOC6518, 2000J(P1)2977>. An example of this approach has been employed in the preparation of the pyrrole 487 from the nitroacetate 488 during a synthesis of (-F)-deoxypyrrololine (Equation 138) <2001JOC11>. Similarly, pyrroles are also formed upon treatment of /3-sulfonylnitroalkane derivatives with ethyl isocyanoacetate <1997J(P1)3161, 2003TL5163>. 

Although a nitro group has a large effect on thermodynamic acidity, rates of proton transfer are not increased by similar amounts. For nitroethane (pA- 8.60 [99]), water catalysed ionization occurs with a rate coefficient [37] of 3.7 x 10"8 sec-1 compared with the value of 1.32 x 10 2 sec-1 for acetylacetone [89] (pif 8.9 [17]) and the value (ca. 102 sec"1) which would be observed for a normal acid [59] with pK 8.5. Since nitroparaffins ionize slowly the reaction may be followed using classical methods and rates of proton transfer to a wide variety of bases have been measured nitroparaffins [100] and ketones were among the first carbon acids to be studied. Corrections may be required for the presence of the aci-isomer. Figure 4 shows results for the rates of base catalysed ionization of ethyl nitroacetate [101] obtained by spectro-photometric measurement of the increase in concentration of the anion (74) or by measuring the rate of bromination, (74) and (75), viz. 

Table 59 presents activation parameters for the decarboxylation of trichloroacetic acid in various basic solvents. Presumably the acid is in the form of its anion in these solvents. The activation parameters fall into a fairly narrow range and the differences presumably represent specific solvation effects. In an acidic solvent, decanoic acid, the activation parameters for the decomposition of potassium trichloroacetate are increased considerably. The values are A/f = 41.4 kcal.mole" and A5 = 27.7 eu . The activation parameters presumably reflect a composite of a prior equilibrium between decanoic acid and the trichloroacetate anion along with decarboxylation of the latter anion. The rate of decarboxylation of sodium nitroacetate is about five times faster in methanol than in water . This effect was attributed to dispersion of the negative charge at the transition state , a process which is more favorable in the less polar methanol solvent. Similarly, the decar-... 

The reaction of diazoazoles with nitro-substituted acetonitriles, as well as ethyl nitroacetate, takes place in a similar manner <1996RJO770, 1997M1103, 2001SC2351>. 

Allyl y3-keto carboxylates 563 undergo facile Pd-catalyzed decarboxylation to form either jr-allylpalladium enolates 565 or a-palladaketone 564. Also rr-allyl-palladium enolates are generated from enol carbonates 566. As summarized below, several transformations to afford 567-573 are possible under different but proper conditions depending on the substituents R [199]. In addition to allyl j6-keto carboxylates, other allyl esters such as allyl malonates, cyanoacetates and nitroacetates undergo similar transformations. With these Pd-catalyzed reactions, a new generation of j6-keto esters and malonate chemistry has been developed. 

Although imino derivatives of nitromalonaldehyde and active methylene compounds often give linear condensation products that could not be cychzed, a-nitio-jS-methylaminoacrolein reacts with diethyl malonate to give ethyl l-methyl-5-nitro-2-pyridone-3-carboxylate (W-150, R = CO2C2HS). Similarly, ethyl a-nitroacetate gives W-150 (R = N02). ... 

The 18-crown-6-cyclic polyether-KBr complex catalyses the homogeneous liquid phase molecular oxygen oxidation of ethylbenzene to the hydroperoxide. The macrobicyclic ligands (cryptands) are strong bases but the rates of proton transfer from ethyl nitroacetate to the free base cryptand and to the mono-protonated cryptand are ca, 10 and 100-fold smaller, respectively, than that of transfer to a normal base of similar basicity. This is attributed either to steric hindrance to proton transfer or to proton transfer occurring only to the thermodynamically unfavourable exo-nitrogen conformation. However, a large kinetic isotope effect = 3.9) is observed for the protonation of cryptand... 

O-acetyl-jS-D-glycopyranosides from 0-, m- and p-02T C H 0 a-nitro esters from methyl nitroacetate, and alkyl phenyl selenides from PhSe". Similarly arenesulfonyl fluorides or isothiocyanates can be produced from arenesulfonyl chlorides and F" or SCN", and arene-carboxylic acid cyanides and isothiocyanates from arenecarboxylic acid chlorides and CN" or SCN ... 

Similarly, ethyl nitroacetate afforded, with 1,4-naphto-quinones, fair yields of condensed isoxazoline derivatives as a result of dehydration followed by elimination or dehydrogenation [80]. Later, more examples of condensations of ethyl nitroacetate and alkenes in the same reaction conditions have been reported to compete with oxidation [81]. The intramolecular version, using allyl nitroacetate 16 in the presence of Cu(II) and Mn(III), gives mainly the bicyclic isoxazoline 17 as the condensation product, predominant over monoelectronic oxidation 18 (Scheme 8.6). Noticeably, the intramolecular cyclization occurs with Cu (II) or Co(II) instead of Mn(III) acetate. As expected, secondary nitro compounds undergo only radical reactions. Condensations are reported to occur via intermediate nitrile... 

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