Isoamyl ether nitrite

Recently, Kim and colleagues have described a new efficient method for the preparation of a-keto esters 48 via a free-radical acylation approach using (phenylsulfonyl) methoxycarbonyl oxime ether 46 as carbonyl equivalent radical acceptor (Scheme 28). The oxime 46 was conveniently prepared from readily available methylphenylsulfonyl acetate 44 by a two-step sequence (via oxime 45) as shown in Scheme 28. Nitrosation of 44 with isoamyl nitrite in the presence of sodium methoxide gave oxime 47 in 78% yield. 

Cycloaddition of oxazoles with arynes provides a route to substituted polycyclic ethers and hydrocarbons (80TL3627). Oxazole (354), for example, reacted with anthranilic acid and isoamyl nitrite to provide the cyclic ether (357) by way of the benzofuran (356). The ether was then treated with zinc in glacial acetic acid to furnish hydrocarbon (358) in 70% yield based on the starting oxazole (Scheme 77). 

Dichloro-3-nitropyridine was reacted with N-ethoxycarbonylpiperazine to give 6-chloro-2-(4-ethoxycarbonyl-l-piperazinyl)-3-nitropyridine. The product, without purification, was heated with ethanolic ammonia in a sealed tube at 120°-125°C to give 6-amino-2-(4-ethoxycarbonyl-l-piperazinyl)-3-nitropyridine (mp 132°-134°C), which was treated with acetic anhydride in acetic acid to give 6-acetylamino-2-(4-ethoxycarbonyl-l-piperazinyl)-3-nitropyridine (mp 168°-169°C). This compound was catalytically hydrogenated in the presence of 5% palladium-carbon in acetic acid to yield 3-amino-6-acetylamino-2-(4-ethoxycarbonyl-l-piperazinyl)pyridine. The obtained 3-amino derivative, without further purification, was dissolved in a mixture of ethanol and 42% tetrafluoroboric acid, and to this solution was added a solution of isoamyl nitrite in ethanol at below 0°C with stirring 20 minutes later, ether was added to the solution. The resulting precipitate was collected by filtration and washed with a mixture of methanol and ether and then with chloroform to yield 6-acetylamino-2-(4-ethoxycarbonyl-l-piperazinyl)-3-pyridine diazonium tetrafluoroborate mp 117°-117.5°C (dec.). 

With the intention of extending the nitrogen chain of tetrazene, tet-razenides 62 and 64 were allowed to react with nitrogen halides as well as their derivatives. The desired objective could not be reached in any case because of decomposition of the expected compounds. Thus, reactions of 62 with nitrosyl chloride (NOX X = Cl) and 64 with isoamyl nitrite (NOX X = 0(/-CsHn)] at low temperature in ether occur according to Eqs. (95) and (96) via 73 and 74 (45), respectively, whereas reactions of 62 with phenyldiazonium chloride (PhN=N Cl ) or tosyl azide (TsN, Ts = P-T0ISO2) at — 78°C develop according to Eqs. (97) and (98), probably via 75 and 76, respectively. 

The isodiazotate salts (19) of 2-amino-3-methyl- and 3-amino-2,5-dimethyl-pyrazines (17, R =R = H R = Me R = R = Me, R = H, respectively) [prepared from the corresponding amine by refluxing with sodium amide in diethyl ether and allowing the resulting sodium salt (18) to react with isoamyl nitrite] on treatment with hydriodic acid gave 2-amino-5-iodo-3-methyl- and 2-amino-5-iodo-... 

The modifications of the Knoevenagel diazotization method include the addition of isoamyl nitrite to an appropriate amine salt suspended in cold acetic acid and the diazotization of amine by the addition of a solution of N2O4 in ether. In addition, a specific method for the preparation of anhydrous diazonium tetrafluoroborate has been developed in which the amine is mixed with an alkyl nitrite and an excess amount of BF3 Et20. For this preparation, the excess BF3 can trap the alcohol and water produced during the diazotization, and the diazonium tetrafluoroborate precipitates from the reaction solution as it is formed. ... 

Isopentyi nitrite. See Isoamyl nitrite Isopentyi nonanoate. See Isoamyl nonanoate Isopentyi octanoate. See Isoamyl octanoate 3-lsopentyloxy-1,2-propanediol. See 1 -Isoamyl glycerol ether... 

Hexamethyl-2,4-cyclohexadienone in ether, through which methylamine has been bubbled 45 min. at room temp., irradiated 3.5 hrs. with the Pyrex-filtered light of a 450 w. Hanovia lamp dienamide (Y 89%) in glacial acetic acid flushed with Ng, satd. with HCl, isoamyl nitrite added dropwise, and heated 4.5 hrs. at 100° -> permethyl-2-pyrone imine (Y 67%) heated 4 hrs. at 160-180° with 5 3 aq. 20%-NaOH-methanol permethyl-2-pyridone (Y 74%). H. Hart, D. A. Dickinson, and W. Y. Li, Tetrah. Let. 1975, 2253 ring opening s. a. G. Quinkert et al., B. 109, 1332 (1976). 

Isobutyl nitrite Butyl alcohol scc-Butyl alcohol t r -Butyl alcohol Ethyl ether Isobutyl alcohol Ethyl sulfide Pyridine Isovaleraldehyde 3-Methyl 2-butanone Isobutyl formate Isopropyl acetate Methyl isobutyrate Isoamyl nitrite tert-Amyl alcohol Isoamyl alcohol... 

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