Isoamyl nitrite

Methyl-5-aminothia2ole-4-carboxylic acid is diazotized with isoamyl nitrite in the presence of furan in 1.2-dichloroethane to give a mixture of products 163 (53%), 164 (33%). 165 (11%), and 166 (3%) (Scheme 104) (334). This reactivity experiment was carried out to examine the possibility of the occurrence of 4,5-dehydrothiazole (hetaryne). Hetaryne intermediates seem not to be involved as an intermediate in the reaction. The formation of 163 through 166 can be rationalized in terms of the intermediacy of 166a. 

Attempts to obtain thiazolynes by treating 5-aminothiazoles with isoamyl nitrite in ethylene chloride were unsuccessful (334). 

In agreement with the theory of polarized radicals, the presence of substituents on heteroaromatic free radicals can slightly affect their polarity. Both 4- and 5-substituted thiazol-2-yl radicals have been generated in aromatic solvents by thermal decomposition of the diazoamino derivative resulting from the reaction of isoamyl nitrite on the corresponding 2-aminothiazole (250,416-418). Introduction in 5-position of electron-withdrawing substituents slightly enhances the electrophilic character of thiazol-2-yl radicals (Table 1-57). 

Me2CH(CH2)20NO, CH2CI2, 25°, 15 min H2O, 63-93% yield." Isoamyl nitrite cleaves aromatic dithioacetals in preference to aliphatic dithioace-tals, and dithioacetals in preference to dithioketals. It also cleaves 1,3-oxathiolanes (1 h, 65-90% yield). 

For(n = 3) Me2CH(CH2)20N0, CH2CI2, reflux, 2.5 h, 65% yield. 1,3-Oxathiolanes are also cleaved by isoamyl nitrite. 

An a-oximino enamine was formed by the reaction of nitrosyl chloride and triethylamine with morpholinocyclohexene 494). Oxime functions have also been introduced into carbonyl conjugated enamines with isoamyl nitrite or NjOj 495). 

Iodine, acetone or DMF, ammonium acetate, it, 2 h. The tritylaminophenyl group is stable to isoamyl nitrite/acetic acid. ... 

This highly lipophilic group is cleaved with isoamyl nitrite in Pyr/AcOH. The use of a lipophilic 5 -phosphate protective group aids in reverse-phase HPLC purification of oligonucleotides. 

A, A-Diethylaminomethyl)anilidate 3-[(C2H5)2NCH2]C6H4NH-Cleavage is effected with isoamyl nitrite in Pyr/AcOH." "... 

Isoamyl nitrite, Pyr, AcOH, AgOAc, benzoic anhydride."... 

Nitrobenzaldehyde has been prepared from />-nitrotoluene by treatment with isoamyl nitrite in the presence of sodium methylate,1 by oxidation with chromyl chloride,2 cerium dioxide,3 or chromium trioxide in the presence of acetic anhydride.4 It can also be prepared by the oxidation of -nitrobenzyl chloride,5 7>-nitrobenzyl alcohol,6 or the esters of -nitrocinnamic acid.7... 

In the older literature isopentyl nitrite is called isoamyl nitrite. 

If an aliphatic amino group is to a COOR, CN, CHO, COR, and so on, and has an a hydrogen, treatment with nitrous acid gives not a diazonium salt, but a diazo compound Such diazo compounds can also be prepared, often more conveniently, by treatment of the substrate with isoamyl nitrite and a small amount of acid. Certain heterocyclic amines also give diazo compounds rather than diazonium salts. ... 

Nitrite compounds are often known as poppers because of the popping noise produced when the capsules containing them are crushed between the fingers. Both amyl nitrite and butyl nitrite are yellowish liquids that evaporate at room temperature. These compounds are distributed under variety of names and are contained in a range of products, such as air fresheners. Iso-amyl nitrite is also available in the United States by prescription. Currently, the primary indication for isoamyl nitrite is for the treatment of cyanide poi-... 

Hydroxyimino-2-phenylacetonitrile has been prepared from benzyl cyanide by reaction with nitrous acid, with isoamyl nitrite and sodium ethoxide, and with butyl nitrite and hydrogen chloride." ... 

Isoamyl nitrite Nitrous acid, isopentyl ester (8) Nitrous acid, 3-methylbutyl ester (9) (110-46-3)... 

As mentioned in last year s Report, aromatic phosphoramidates have been used to protect 5 -phosphoryl groups in the stepwise synthesis of oligodeoxyribonucleotides. The appropriate monomer units are coupled with DCC and the phosphoramidate protecting group is removed when required with isoamyl nitrite. A rapid and general preparative method for oligonucleotides has been developed based on phosphoramidates of the highly lipophilic 4-aminophenyltriphenylmethane (25). Purification of... 

Ethyl formate34,52 or orthoformate5 3,54 reacts with two equivalents of phenylhydrazine to yield 1,5-diphenylformazan (11) the reaction takes place under acidic conditions and involves an oxidation. Under basic conditions, ethyl nitrate reacts at the methylene position to yield 3-methyl-1,5-diphenylformazan (37) which can also be obtained from the reaction of phenyl-azoethane (38) with isoamyl nitrite (Scheme 4).8,68 Aryl hydrazines react with a variety of s-triazines (39) to yield 1,5-diaryl formazans with hydrogen, methyl, or phenyl groups in the 3-position as in 40 (Eq. 6).56 Hydrazines have also been reported to react with benzotrichloride55,658 and sym-diamino tetrazine659 to yield formazans. 

The earliest oxidations were effected with nitrous fumes and later with mercuric oxide and isoamyl nitrite.74 Lead tetraacetate in acetic acid is in many cases the reagent of choice, but the removal of by-products can present some difficulties.75 IV-Haloimides and amides in alcoholic solutions have been reported to yield essentially pure tetrazolium salts76 and have been found specially useful in the preparation of heteroaryl-substituted tetrazolium salt.77,78 The novel formazans 49 have been successfully oxidized to 50 using 7V-chloro succinimide (Eq. II).79 tert-Butyl hypo-... 

Compound 120 is also obtained in 36% yield by diazotization of 7-amino-methylbicyclo[3.3.1]nonan-3-ol with sodium nitrite and acetic acid in aqueous solution at 80-90°C and in 55% yield with isoamyl nitrite in acetic acid at 80-85°C.152... 

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>. 

Electrophilic substitution of the ring hydrogen atom in 1,3,4-oxadiazoles is uncommon. In contrast, several reactions of electrophiles with C-linked substituents of 1,3,4-oxadiazole have been reported. 2,5-Diaryl-l,3,4-oxadiazoles are bromi-nated and nitrated on aryl substituents. Oxidation of 2,5-ditolyl-l,3,4-oxadiazole afforded the corresponding dialdehydes or dicarboxylic acids. 2-Methyl-5-phenyl-l,3,4-oxadiazole treated with butyllithium and then with isoamyl nitrite yielded the oxime of 5-phenyl-l,3,4-oxadiazol-2-carbaldehyde. 2-Chloromethyl-5-phenyl-l,3,4-oxadiazole under the action of sulfur and methyl iodide followed by amines affords the respective thioamides. 2-Chloromethyl-5-methyl-l,3,4-oxadia-zole and triethyl phosphite gave a product, which underwent a Wittig reation with aromatic aldehydes to form alkenes. Alkyl l,3,4-oxadiazole-2-carboxylates undergo typical reactions with ammonia, amines, and hydrazines to afford amides or hydrazides. It has been shown that 5-amino-l,3,4-oxadiazole-2-carboxylic acids and their esters decarboxylate. 

Condensations of 5-methyl-substituted 1,2,4-thiadiazoles with aromatic aldehydes lead to 5-styrylthiadiazoles. With carboxylic acid esters, ethoxalyl derivatives are formed, and isoamyl nitrite produces the corresponding oximes <1982AHC285>. These reactions are restricted exclusively to the 5-methyl-substituted 1,2,4-thiadiazoles reflecting the greater reactivity of substituents in the 5-position compared to the 3-position in 1,2,4-thiadiazoles. 

Isoamyl acetate, i91 Isoamyl alcohol, ml63 seolsoamyl alcohol, ml64 Isoamyl bromide, b362 Isoamyl chloride, cl69a Isoamyl nitrite, i92... 

Attempts to utilize an in situ diazotization procedure (1.2 equiv. isoamyl nitrite, acetic acid, 25 °C, 30 min) [58,60-62] for DNA cleavage were made via generation of diazonium compound 17 directly from commercially available 9-aminofluorene (Fig. 18) [58]. However, addition of this solution to aqueous buffers (pH = 4-7) did not produce any DNA cleavage neither did the addition of cuprous chloride, which had been demonstrated to be successful in activating diazonium compounds for DNA cleavage [60-62]. This may be explained by ... 

The submitters used amyl nitrite U.S.P. from Mallinckrodt Chemical Works isoamyl nitrite supplied by Matheson, Coleman and Bell is apparently the same material. They found that other alkyl nitrites (ethyl, w-butyl, 1-butvl, amyl) may be used with equal success. Subsequent to the checking of this procedure, they reported that the amount of nitrite can be reduced to a 20% molar excess. 

A. Benzenediazonium-2-carboxylate. A solution of 34.2 g. (0.25 mole) of anthranilic acid (Note 1) and 0.3 g. of trichloroacetic acid (Note 2) in 250 ml. of tetrahydrofuran (Note 3) is prepared in a 600-ml. beaker equipped with a thermometer and cooled in an ice-water bath. The solution is stirred magnetically, and 55 ml. (48 g., 0.41 mole) of isoamyl nitrite (Note 4) is added over a period of 1-2 minutes. A mildly exothermic reaction occurs, and the reaction mixture is maintained at 18-25° and stirred for a further 1-1.5 hours. A transient orange to brick-red precipitate may appear (Note 5) which is slowly converted to the tan product. When the reaction is completed, the mixture is cooled to 10°, and the product is collected by suction filtration on a plastic Buchner funnel and washed on the funnel with cold tetrahydrofuran until the washings are colorless. (Caution The filter cake should not be allowed to become dry.) The benzene-diazonium-2-carboxylatc is then washed with two 50-ml. portions of 1,2-dichloroethane to displace the tetrahydrofuran, and the solvent-wet material is used in the next step (Notes 6, 7, and 8). 

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