Open-chain nitrogen compounds. Part II. Preparation, characterization, and degradation of 1(3)-Aryl-3(1)-methyltriazenes; the effect of substituents on the reaction of diazonium salts with methylamine

Abstract

Treatment of the diazonium salts, X•C6H4N2+, with aqueous methylamine affords good yields of the monomethyltriazenes, X•C6H4•N=N•NHMe, when the substituent is a strongly electron-withdrawing group (X = o-, m-, and p-NO2; o-, m-, and p-CO2R; p-CN and p-COCH3). Preparation of the triazene from the p-bromobenzene diazonium salt was accompanied by formation of a pentaazadiene. Monomethyltriazenes were not obtained when diazonium salts containing other substituents (X = H, p-CH3, o-CF3, p-Cl, p-F, p-NMe2, p-OH, p-OCH3, p-Ph, p-NHCOCH3) were treated with methylamine. In these cases the products were either pentaazadiene, or 1,3-diaryltriazenes or unstable materials. The monomethyltriazenes vary considerably in stability and give rise to a number of different degradation products, which were either diaryltriazenes or 3-alkyl-1,3-diaryltriazenes or simply arylamines. 1(3)-(p-Nitrophenyl)-3(1)-methyltriazene was found to be a moderately effective methylating agent.

Rh(III)Cp* and Ir(III)Cp* Complexes of 1-[(4-Methyl)phenyl]-3-[(2-methyl-4′-R)imidazol-1-yl]triazenide (R = t-Bu or H): Synthesis, Structure, and Catalytic Activity

“…Moreover, a metal hydride was also observed (−14.62 ppm) in the absence of base when 7 was heated to 70 °C for 4 h in 2-propanol (Figure S69). In addition, compound 10 was synthesized from triazene 9 in the same manner as complexes 4 – 7 (eq ). …”

“…In addition, the presence of the imidazole moiety in the structure of precatalysts 6 and 7 accelerate the catalytic hydrogenation of 11a,b to give species B. Moreover, species A was not detected in most of the experiments conducted without base, suggesting that the hydrogenation follows the order 11a,b → B → C. For instance, when complex 6 was treated with 1 equiv of 11a in THF-d 8 at 70 °C, isomerization of the double bond took place over two positions to produce 3-hexen-2-one (12), which gives rise to a new set of olefinic signals in the 1 H NMR spectrum at 6.81 and 5.99 ppm (Figures S115 and S116). Under these reactions conditions, the isomerization of 11a to 12 was slow (≈16% in 3 h).…”

Targeting Gliomas: Can a New Alkylating Hybrid Compound Make a Difference?

“…The synthesis of HYBCOM ( 6 ) comprised the steps described in Scheme . As previously reported, diazotation of the commercially available 4-aminobenzonitrile 1 with nitrous acid led to the formation of the diazonium salt 2 and the subsequent reaction with HCHO/MeNH 2 provided the hydroxymethyltriazene 3 . In the presence of a threefold excess of MeNH 2 , the hydroxymethyltriazene 3 decomposed into the corresponding monomethyltriazene 4, with the elimination of formaldehyde .…”

Open-chain nitrogen compounds. Part V. Hydroxymethyltriazenes: synthesis of some new alkyl homologues of the anti-tumour 3-methyl-3-hydroxymethyltriazenes and preparation of the derived acetoxymethyl-, benzoyloxymethyl-, and methoxymethyltriazenes

“…Accordingly, a sample of the I-p-cyanophenyl-3-methyltriazene was prepared (10) and was found to react in suspension in aqueous formaldehyde at 0°C very readily to afford an excellent yield of I-p-cyanophenyl-3-hydroxymethyl-3-methyltriazene (1 X = CN, R = Me), which was identical with a sample prepared by Method A. This method is now being explored more extensively in this laboratory and will be reported more fully at a later date.…”

“…Reaction of I -p-cya1zophetzyl-3-rnetl1yltriazer~e with fortn~zl~lehyde 1-p-Cyanophenyl-3-methyltriazene was prepared by reaction of p-cyanobenzene diazonium chloride with methylamine, according to our published method (10). The monomethyltriazene (0.7 g) was suspended in water (20 mL) at 0°C and 37% aqueous formaldehyde (17.7 g) was added to the suspension.…”