Isoamyl nitrite, nitrosation with

Instead of sodium nitrite, isoamyl nitrite is sometimes used as a nitrosating agent in synthesis of the benzotriazole ring. With this reagent, the reaction conditions are very mild allowing survival of acid sensitive groups. In an example of such a reaction, methyl 3,4-diamino-2-methoxybenzoate 1286 is treated with isoamyl nitrite at room temperature. The reaction is fast and provides methyl 4-methoxybenzotriazole-5-carboxylate 1287 in 62% yield, isolated by simple filtration off the precipitate (Equation 31) <2006JME4762>. 

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. 

The literature (83JHC385) reports that nitrosation of benzisoxazoles 36 with isoamyl nitrite and sodium methoxyde results in a mixture of 37Z... 

Nitrosation. 2,6-Diaminopyridine with nitrous acid forms the 3-nitroso derivatives. Nitrosation has been much used in pyrimidine chemisty nitrosation of pyrimidines occurs readily in the presence of three electron-releasing substituents pyrimidine-4,6-diamine is also nitrosated to the blue 5-nitroso derivative treatment of 4-amino-2,6-dimethoxypyrimidine 137 with isoamyl nitrite in DMSO at room temperature gives the 5-nitroso derivative 138 in 75% yield <2002SL255>. 

The vinylogous nitroso-substituted TTF 807 was obtained in the Wittig reaction of the phosphonium salt 800 with the aldehyde 806. The second nitroso group in 807 was introduced by nitrosation using isoamyl nitrite to give 808 (Scheme 122) <1997JOC2616>. 

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