Isocyanide, ethyl

C2H5I + AgCN - C2H5NC-AgI C2H5NC-AgI + 2KCN - C2H5NC + KAg(CN)2 + KI 

Caution This preparation should be carried out in a wcll-vcntilaled hood because ethyl isocyanidc has a vile odor. Since ethyl 

Sometimes the liquid crystallizes to a dense solid which immobilizes the stirrer if it has not been raised. The crystallization has no effect on subsequent steps except to necessitate a longer period of stirring after the potassium cyanide is added. 

The aqueous cyanide solution, which is very toxic, can be disposed of by flushing it down the drain with a large volume of water. 

The submitters used an 18-in. spinning-band column (inside diameter 10 mm.). The checkers employed a 12-in. helix-packed column. 

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Ethyl 2,4-diphenylbutanoate, 47, 72 Ethyl 2,3-diphenylpropionate, 47, 74 Ethyl isocyanide, 46, 76, 77 Ethylmagnesium bromide, use with ferric chloride in cyclization of di-chloroacetone -tolylmagnesium bromide adduct to l-/>-tolylcy-clopropanol, 47,108 Ethyl nit ropheny lace late, reaction... 

Ethyl indole-2-carboxylate, 43,40 Ethyl isocyanide, 41, 15 N-Ethyi-N-methylaniline, 43,47 Ethyl o-nitrophenylpyruvate, potassium salt of, 43, 40... 

The present method utilizes dichlorocarbene generated by the phase-transfer method of Makosza4 and Starks.5 The submitters have routinely realized yields of pure distilled isocyanides in excess of 40%.6 With less sterically hindered primary amines a 1 1 ratio of amine to chloroform gives satisfactory results. Furthermore, by modifying the procedure, methyl and ethyl isocyanides may be prepared directly from the corresponding aqueous amine solutions and bromoform.7 These results are summarized in Table I. 

Ethylenedioxybutyl)-3-trichloro-acetamido-l-cyclohexene, 58, 9, 11 Ethylene glycol, 56, 44 Ethyl a-fluoro-l-naphthaleneacetate, 57, 73 Ethyl 2-fluoropropanoate, 57, 73 3-Ethylhexane, 58, 3, 4 3-ETHYL-l-HEXYNE, 58, 1, 2, 3, 4 Ethylidenecyclohexane, 59, 46 Ethyliodide, 59, 133 Ethyl 2-iodo-3-nitropropionate, 56,65 Ethyl isocyanide, 55, 98 Ethyl isocyanoacetate, 59,184 l-Ethyl-4-isopropylbenzene, 55,10 Ethyl levulinates, 5-substituted, 58, 81 ETHYL 2-METHYL1NDOLE-5CARBOXY-LATE, 56, 72... 

It is very endothermic (AH°f (g) +150.2 kJ/mol, 3.66 kJ/g). A sample exploded when heated in a sealed ampoule [1], and during redistillation at 59°C/1 bar, a drop of liquid fell back into the dry boiler flask and exploded violently [2], The explosive decomposition has been studied in detail [3], and existing data on thermal explosion parameters have been re-examined and discrepancies eliminated [4], See Ethyl isocyanide... 

N-Methylethylamine has been prepared by heating ethyl-amine with methyl iodide in alcohol at 100° 3 by the hydrolysis of N-methyl-N-ethylarenesulfonamides,4-5 -nitroso-N-methyl-N-ethylaniline,6 or methylethylbenzhydrylidene ammonium iodide 7 by catalytic hydrogenation of ethyl isocyanate or ethyl isocyanide 8 and by the reduction of ethyl isocyanate by lithium aluminum hydride,9 of N-methylacetisoaldoxime by sodium amalgam and acetic acid,10 or of a nitromethane/ethylmagnesium bromide adduct by zinc and hydrochloric acid.11... 

In addition to the 2 nm shift in the absorption maximum, the two cytochromes can be distinguished by the use of ethyl isocyanide interaction spectra (6, 7) and various inhibitors of the monooxygenase activity (Figure 2 and Table III). The relative magnitude of the ethyl isocyanide-cytochrome P-1+50 interaction spectral peaks at —1+30 and —1+55 nm is pH dependent (6j and if the absorbance differences are plotted as functions of pH, there is a cross-over point at a certain pH which is characteristic for a particular form of cytochrome P-1+50 pH 6.9 for cytochrome P-1+1+8 and pH 7-5-7.6 for PB induced or control cytochrome P-1+50 (6, 21). The cytochrome P-1+50 of apparently uninduced trout species (Salmo trutta lacustris) has been shown by us to have the pH cross-over point for ethyl isocyanide interaction spectrum at pH 7.8 (2l) and the absorption maximum of the reduced trout liver cytochrome P-1+50. 00 complex is 1+50 nm, nevertheless its catalytic and inhibitory properties (2l)(Table III) are similar to those of cytochrome P-1+1+8. 

Figure 2. Spectra of ethyl isocyanide-ferrocytochrome P-450 complexes. Female... 

Bassett, J.-M., Green, M., Howard, J.A.K. and Stone, F.G.A. (1978) Formation of nona(ethyl isocyanide)diiron from penta(ethyl isocyanide)iron and reaction of penta(tert-butyl isocyanide)iron with diphenylacetylene X-ray crystal structures of nona(ethyl isocyanide)diiron and tris(tert-butyl isocyanide) l,4-bis-(tert-butylimino)-2,3-diphenylbuta-l,3-diene ... 

The present procedure is the best way of preparing aliphatic isocyanides boiling above ethyl isocyanide. It has been applied to the synthesis of the following isocyanides 6 isopropyl (38%), -butyl (61%), te -butyl (68%), and benzyl (56%). In preparing isopropyl isocyanide or teri-butyl isocyanide, the petroleum ether should be of boiling point 30-35°, as otherwise it is difficult to separate these low-boiling isocyanides in the indicated yield, and,... 

Ethyl 6,7-dimethoxy-3-methylin-dene-2-carboxylate, 40, 43 Ethyl formate, reaction with cyclo-hexylamine, 41, 14 Ethyl isocyanide, 41, 15 Ethyl trichloroacetatc for generation of dichlorocarbene, 41, 76... 

Aromatic isocyanides can also be prepared conveniently by the dehydration of the corresponding formamides by phosphorus oxychloride, but much better results are obtained if the reaction is done in the presence of potassium fer/-butoxide rather than pyridine.6 Neither method of dehydrating formamides has yet been used to prepare methyl or ethyl isocyanide because their low boiling points make them difficult to isolate from the reaction mixture hence, until a suitable dehydration procedure is worked out, they are best made by reaction of the corresponding alkyl iodide with silver cyanide. ... 

In the reduced state, cytochromes P-450 may also bind certain ligands to give particular difference spectra. The most well known is that which occurs when carbon monoxide binds giving an absorption maximum at 450 nm. A type III spectrum gives two peaks at 430 and 455 nm after binding of certain compounds such as ethyl isocyanide or methylenedioxyphenyl compounds to the reduced enzyme. The latter form stable complexes with the enzyme and are also inhibitors. 

The initial experiences with polyisocyanides, especially solubilities and some Debye-Scherrer X-ray data (3), and an consideration of the most probable molecular structure (4), led to an early tentative conclusion that poly(a-phenyl-ethyl isocyanide) and poly(conformational model of a tightly wound helix with an overall shape of a cylindrical rod of about 15 A diameter (3). 

Primary alkyl isocyanides are known not to comply simply to homopolymerization. It was recently reported that polyisocyanides prepared with nickel(II) compounds varied in color from yellow to black (22,23). The latter occurred at preparative temperatures in excess of 25° C, or when polymer non-solvents or acids were used. Further, the addition of acids to solutions or suspensions of the yellow polymers also led to black compounds. The NMR spectrum of a soluble polymer sample (i.e. MVPO = 1100) of black poly(ethyl isocyanide) shows methylene resonance shifts to values as occur in nitriles, which were interpreted as giving evidence of rearrangement to a polycyanide... 

Fig. 11. Concentration dependence of reduced viscosities of various unfractionated samples of poly[(a-carboxymethyl)ethyl isocyanide] in 1,2-dichloroethane at 30° C (9)...

The viscosity behavior of poly[(a-carboxymethyl)ethyl isocyanide] may be studied in neutral organic solvents. The concentration dependence of its reduced specific viscosity in 1,2-dichloroethane is shown in Fig. 11. A linear dependence indicates that the coefficients of higher concentration terms of the usual virial equations are negligibly small—a case which should be found with molecules, such as stiff rods, that give few intermolecular entanglements in dilute solution. 

The unusually high observed initial intrinsic viscosity was at first thought to be due to molecular aggregation of polymer chains, made possible by presumed interaction of the carboxyl ester groups. Molecular association is known in many polymeric systems, but in those cases the association process is also apparent in osmometric data. No evidence of association is observed in the osmometric data of poly[(a-carboxymethyl)ethyl isocyanide]. Moreover, it would be expected that, if molecular association would have taken place, different values of [>7] would have been observed upon changing of solvents. Such change is not observed upon addition of triethyl amine (i.e. 10% volume) to 1,2-dichloroethane, or by solvent change to p-dioxane. 

The viscometric data of poly[(a-carboxymethyl)ethyl isocyanide] in simple solvents surprisingly also show a very slow temperature-dependent viscosity decay phenomenon (8,9). Still more surprising, gel permeation chromatography shows no evidence of changes in the hydrodynamic volume over the time periods of decay. 

Poly[(a-carboxymethyl)ethyl isocyanide] may be saponified with sodium hydroxide in methanol at room temperature in 5 days or at reflux in 20hrs, attended by discoloration. Aqueous solutions of the isolated salt do not show viscosities expected of polyanions. Attempt to isolate the free polycarboxylic acid by acidification is accompanied by decarboxylation, which is to be expected on the basis of its chemical structure (55). 

Poly(/ -phenylethyl isocyanide) was similarly prepared and fractionated (14). A comparison between the hydrodynamic properties of poly(/T and poly(a-phenylethyl isocyanide) showed, that while the latter was characterized by its intrinsic lack of molecular flexibility, the former was relatively a flexible chain. This was manifested in the values estimated for the shape factor and the radius of gyration. Accordingly, two general conformations in dilute solution are ascribed to poly(phenylethyl isocyanides) a nearly rigid, rodlike helix to poly(a-phenyl-ethyl isocyanide), and an undulating, more randomly orienting chain to poly(/l-phenylethyl isocyanide). 

Methyl cyanide CHiCN, bp 82 C. formed by reaction of (I) methyl iodide and potassium cyanide. (7) acetamide and phosphorus pentoxide Methyl isucyanide CHiNC. hp 60 C. formed by reaction (l)ol methyl iodide and silver cyanide. (2) of nielhylamine. chloroform and NaOH solution warmed. Ethyl isocyanide C.H NC. bp 78 C. Phenyl isocyanide CVIUNC. hp 78 C at 40 torr pressure. 

An explosion involving ethyl isocyanide has been reported.2 For this reason, prudence dictates the use of adequate shielding in all heating operations. 

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