Butyl nitrite

Similar reactions have been carried out by various investigators using ethyl nitrite, amyl nitrite,and other alkyl nitrites in aqueous or alcoholic solution in the presence of potassium hydroxide or potassium ethylate. In the procedure given below butyl nitrite is used. It is more easily prepared and handled than ethyl nitrite. It may also be used for the preparation of sodium azide. 

Eighty-seven milliliters of concentrated sulfuric acid (1.5 mol H2SO4) is poured into 60 ml. of water. The mixture is cooled to 0° in an ice-salt bath and maintained at this temperature while 222 g. (3 mols) of n-butyl alcohol is added slowly, with constant agitation. During the course of an hour this mixture is then introduced beneath the surface of a cold (0°) solution of 228 g. (3.3 mols) of sodium nitrite dissolved in 900 ml. of water, which is contained in a 

beaker. The nitrite solution should be well cooled in an ice-salt bath and the solution agitated during the addiction of the butyl alcohol-sulfuric acid mixture. The butyl nitrite forms as a yellow oily layer that floats on the surface of the aqueous solution. This layerf is separated, and the crude product is washed three times with 60-ml. portions of a solution of 45 g. of salt and 5 g. of sodium bicarbonate in 180 ml. of water. The product is dried over anhydrous sodium sulfate. Yield 270-289 g. (87 to 93.5 per cent). 

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Cupferron, the ammonium salt of the N-nitroso derivative of phenylhydr-oxylamine, is prepared by passing ammonia gas into an ethereal solution of phenylhydroxylamine and n butyl nitrite ... 

In addition to the Hquid-phase -butyl nitrite (BN) process, UBE Industries has estabHshed an industrial gas-phase process using methyl nitrite (50—52). The oudine of the process is described in Eigure 4 (52). This gas-phase process is operated under lower reaction pressure (at atmospheric pressure up to 490 kPa = 71 psi) and is more economical than the Hquid-phase process because of the foUowing reasons owing to the low pressure operation, the consumption of electricity is largely reduced (—60%) dimethyl oxalate (DMO) formation and the methyl nitrite (MN) regeneration reaction are mn... 

Equations 4-8 illustrate some mild methods that can be used to cleave amides. Equations 4 and 5 indicate the conditions that were used by Woodward and Eschenmoser, respectively, in their synthesis of vitamin B,2- Butyl nitrite," nitrosyl chloride, and nitrosoniurn tetrafluoroborate... 

Nitrosyl chloride [55], nitrosyl fluoride-hydrogen fluoride liquid complexes (NOF3HF, NOF 6HF) [56], nitrous acid-hydrogen fluoride solutions [57, 5 ] nitrogen trioxide (prepared in situ from nitric oxide and oxygen) [59] and rert-butyl nitrite-hydrogen fluoride-pyndine [60] have been substituted for sodium nitrite in the diazotization step... 

Equations 1-10 illustrate some mild methods that can be used to cleave amides. Equations 1 and 2 indicate the conditions that were used by Woodward and Eschenmoser, respectively, in their synthesis of vitamin B12. Butyl nitrite, nitrosyl chloride, and nitrosonium tetrafluoroborate (NO BF4 ) have also been used to cleave amides. Since only tertiary amides are cleaved by potassium -butoxide (eq. 3), this method can be used to effect selective cleavage of tertiary amides in the presence of primary or secondary amides.(Esters, however, are cleaved by similar conditions.) Photolytic cleavage of nitro amides (eq. 4) is discussed in a review. 

The homolog of epinephrine in this series is a potent vasoconstrictor. Reaction of 3,4-dimethoxypropiophenone with butyl nitrite leads to nitrosation at the a position (36). Stepwise reduction of the nitrosoketone leads to the amino alcohol (37). Removal of the methyl ether affords racemic 38. Resolution of this last followed by separation of the (-) isomer gives levonor-defrine (38). ... 

Trimethyl Borate, (CH3)3B03, did not gel any of the NC s Trimethyl Phosphate, (CH3)3P03, gelatinized all three. NC s rapidly and completely Dimethyl Sulfate. (CH3)2S04, gelatinized li and 12% N NC s rapidly and completely, the 13% N NC incompletely Dimethyl Sulfite, (CH3)2S03, gelatinized all three NC s rapidly and completely Butyl Nitrite,... 

Doyle and Bryker (1979) reported high yields of arenediazonium tetrafluoroborates when aromatic amines were reacted with tert-butyl nitrite and trifluoroboro etherate in CH2C12. It is likely that nitrosyl fluoride is formed as nitrosating reagent by fluoride-alkoxy exchange. 

The Pd°-catalyzed arylations using arenediazonium tetrafluoroborates are limited to those diazonium salts that can be manipulated at room temperature. The reaction can, if necessary, be performed at temperatures up to 50 °C by using a mixture of an arylamine and tert-butyl nitrite in chloroacetic acid or in a mixture of chloroacetic and acetic acid (Kikukawa et al., 1981a). Styrene reacted with fourteen arylamines in the presence of 5 mol-% Pd(dba)2 to give the corresponding substituted stilbenes in yields of 46-97%. It is important for good yields to carry out these reactions in an acidic system. Without acid the yield was low (11%), and diazo tars were also formed. 

With regard to the mechanism of these Pd°-catalyzed reactions, little is known in addition to what is shown in Scheme 10-62. In our opinion, the much higher yields with diazonium tetrafluoroborates compared with the chlorides and bromides, and the low yields and diazo tar formation in the one-pot method using arylamines and tert-butyl nitrites (Kikukawa et al., 1981 a) indicate a heterolytic mechanism for reactions under optimal conditions. The arylpalladium compound is probably a tetra-fluoroborate salt of the cation Ar-Pd+, which dissociates into Ar+ +Pd° before or after addition to the alkene. An aryldiazenido complex of Pd(PPh3)3 (10.25) was obtained together with its dediazoniation product, the corresponding arylpalladium complex 10.26, in the reaction of Scheme 10-64 by Yamashita et al. (1980). Aryldiazenido complexes with compounds of transition metals other than Pd are discussed in the context of metal complexes with diazo compounds (Zollinger, 1995, Sec. 10.1). 

Diazonium ions generated from ordinary aliphatic primary amines are usually useless for preparative purposes, since they lead to a mixture of products giving not only substitution by any nucleophile present, but also elimination and rearrangements if the substrate permits. For example, diazotization of n-butylamine gave 25% 1-butanol, 5.2% 1-Chlorobutane, 13.2% 2-butanol, 36.5% butenes (consisting of 71% 1-butene, 20% trans-2-butene, and 9% cw-2-butene), and traces of butyl nitrites. ... 

Primary alkyl amines RNHi can be convertedto alkyl halides by (1) conversion to RNTs2 (p. 447) and treatment of this with I or Br in DMF, or to N(Ts)—NH2 derivatives followed by treatment with NBS under photolysis conditions, (2) diazotization with terr-butyl nitrite and a metal halide such as TiCU in DMF, or (3) the Katritzky pyrylium-pyridinium method (pp. 447,489). Alkyl groups can be cleaved from secondary and tertiary aromatic amines by concentrated HBr in a reaction similar to 10-71, for example,... 

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-... 

Although, to our knowledge, the effects of inhalation of amyl nitrite or butyl nitrite on glutamatergic neurotransmission have not been studied, NO, the potent compound that mediates the peripheral effects of nitrites in blood vessels, if released in the CNS when nitrites are inhaled, may potentially affect the glutamatergic system. NO has been reported to act directly on the postsynaptic NMDA receptor, where it can increase or decrease NMDA-mediated currents and subsequent calcium influx (Aizenman et al. 1990 Dingledine et al. 1999 Manzoni et al. 1992). 

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