Methyl acetate isocyanide

The direct combination of selenium and acetylene provides the most convenient source of selenophene (76JHC1319). Lesser amounts of many other compounds are formed concurrently and include 2- and 3-alkylselenophenes, benzo[6]selenophene and isomeric selenoloselenophenes (76CS(10)159). The commercial availability of thiophene makes comparable reactions of little interest for the obtention of the parent heterocycle in the laboratory. However, the reaction of substituted acetylenes with morpholinyl disulfide is of some synthetic value. The process, which appears to entail the initial formation of thionitroxyl radicals, converts phenylacetylene into a 3 1 mixture of 2,4- and 2,5-diphenylthiophene, methyl propiolate into dimethyl thiophene-2,5-dicarboxylate, and ethyl phenylpropiolate into diethyl 3,4-diphenylthiophene-2,5-dicarboxylate (Scheme 83a) (77TL3413). Dimethyl thiophene-2,4-dicarboxylate is obtained from methyl propiolate by treatment with dimethyl sulfoxide and thionyl chloride (Scheme 83b) (66CB1558). The rhodium carbonyl catalyzed carbonylation of alkynes in alcohols provides 5-alkoxy-2(5//)-furanones (Scheme 83c) (81CL993). The inclusion of ethylene provides 5-ethyl-2(5//)-furanones instead (82NKK242). The nickel acetate catalyzed addition of r-butyl isocyanide to alkynes provides access to 2-aminopyrroles (Scheme 83d) (70S593). 

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... 

Methylhydroxybenzene, see 2-Methylphenol p-Methylhydroxybenzene, see 4-Methylphenol Methylisoamyl acetate, see sec-Hexyl acetate Methyl isobutenyl ketone, see Mesityl oxide Methylisobutylcarbinol acetate, see sec-Hexyl acetate Methyl isobutyl ketone, see 4-Methyl-2-pentanone Methyl isocyanide, see Dimethylamine, Methyl isocyanate Methyl ketone, see Acetone... 

Isocyanate, chlorosulfonyl-, 56, 41 Isocyanate, 2-propyl-, 56, 96 Isocyanide, benzyl-, 55, 98 Isocyanide, butyl-, 55, 98 ISOCYANIDE, tert-bulyl-, 55, 96 Isocyanide, cyclohexyl, 55, 98 Isocyanide, dodecanyl-, 55, 98 Isocyanide, ethyl-, 55, 98 Isocyanide, methyl-, 55, 98 Isocyanide, phenyl-, 55, 98 Isophorone, 57, 113 Isopropenyl acetate, 57, 113 Isopropyl alcohol, 58, 78,157 Isopropyl ether, 58, 45, 52 Isopropyl fluoride,58,78 Isopropylurea-polystyrene, 56, 96 Isoquinohne, 56, 20... 

Enantiopure acetal 237 and a-methyl benzylamine 238 were mixed in methanol in the presence of tert-butyl isocyanide and benzoic acid to afford a separable diastereomeric mixture of the Ugi reaction 4CR product 239. Debenzylation using... 

The fused pyrrole ring system (204) has been obtained by the reaction of 17/3-hydroxy-17-methylandrosta-l,4-dien-3-one with tosylmethyl isocyanide in the presence of sodium hydride in DMSO,92 and 17/3-hydroxy-17-methyl-7-oxa-5o -androstano-[3,2-c]- (205) or -[2,3-d]-isoxazoles (206 X = O) have been prepared by treating 7-oxa-2-(hydroxymethylene)-17/3 -hydroxy-17-methyl-5 a -androstan-3-one with hydroxylamine hydrochloride.93 In the presence of pyridine, the isox-azole (206 X = O) is formed, but when the reaction is catalysed by sodium acetate in acetic acid the isomeric steroid (205) results. Cycloaddition of hydrazine hydrate to the same 2-hydroxymethylene-7-oxa-steroid results in the [3,2-c]pyrazole (206 X = NH). A similar addition is encountered in the reactions between 3/3-hydroxy-16-(hydroxymethylene)-5a-androstan-17-one and the substituted hydrazines RNHNH2 (R = H, o-COC6H4NH2, or p-COQHUNH ,) when the corresponding [17,16-c]pyrazoles (207) are formed after cyclization of the intermediate hydrazones.94... 

The reaction of dimethylformamide diethyl acetal with the carbanion which forms when the isocyanide (31) is metalated gives an alkene (32) which reacts with methyl iodide to give an imidazole product (79LA1444). In the presence of base, 2-isocyanoalkane nitriles (33) react with alcohols, thiols or hydrogen sulfide to form imidazoles which have an oxygen or sulfur substituent at C-5 (Scheme 16) (79LA1602). 

Many acrylic copolymers are currently used in the textile industry as binders for nonwoven fabrics. The purpose of these fibers is to stabilize the material. In many instances, these copolymers are used in conjunction with amino resins. Casanovas and Rovira have done a study of methyl methacrylate-ethyl acrylate-N-methylol-acrylamide by PY/GC-MS. Among the products identified were methane, ethylene, propene, isobutene, methanol, propionaldehyde, ethanol, ethyl acetate, methyl acrylate, methyl isobutyrate, ethyl acrylate, methyl methacrylate, n-propyl acrylate, and ethyl methacrylate. In this sample, clearly monomer reversion is the primary degradation process occurring however, several other degradation mechanisms are at work. When the sample contains an amino resin in the mixture, acrylonitrile is observed in the pyrogram. Another effect of the amino presence was a marked increase in the amount of methanol detected. Other products detected were meth-oxyhydrazine, methyl isocyanate, and methyl isocyanide. 

In connection with our project related to peptidomimetics, we had the occasion to examine the U-4CR of N-methyl-hydroxylamine 105a (R= Me), heptanal, benzylisocyanide 106a, and acetic acid, developed earlier by Guanti and coworkers [54]. Under the conditions used by the above authors (MeOH, rt), we did obtain the expected U-4CR adduct 107a (R=Me) and the nonacylated adduct 108a (R=Me) in yields of 45% and 18%, respectively (Scheme 15.30). However, N-benzyl-2-oxoheptanamide 109 was also produced unexpectedly in 10% isolated yield. The formation of 109 represented a formal oxidative couphng of aldehyde and isocyanide [55]. 

The Passerini reaction has also been utilized as a method for the homologation of heterocyclic carboxaldehydes. Studies by Weinreb and coworkers, directed toward the synthesis of amphimedine, have used a Passerini reaction for the homologation of the methoxypyridine derivative 65 with methyl isocyanide and acetic acid in methanol to give 66 in 77% yield. 

Scheme 10.45. The Passerini reaction. Methyl isocyanide (CH3NC) is shown undergoing reaction with propanone (acetone, CH3COCH3) in ethanoic acid (acetic acid, CH3CO2H). The product, after rearrangement is the acetate ester of the M-methylamide of 2-hydroxy-2-methylpropanoic acid (see Passerini, M. Gazz- Chim. Ital., 1921,51,126 Ugi, I. Angew. Chem. Int. Ed. Engl, 1962, i, 8).

Indoles.—Formation. Phenacyltriphenylarsonium bromide, Ph3AsCH2COPh Br , reacts with aniline to give 2-phenylindole. o-Tolyl isocyanide (306) is selectively lithiated at the methyl group by lithium di-isopropylamide at —78°C warming the product to room temperature, followed by aqueous workup, yields indole almost quantitatively. The ester (307) cyclises to the indole (308) in the presence of palladium acetate and triphenylphosphine. Treatment... 

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