Nitrosation of 1-phenyl-3-(pyridylmethyl)ureas and the reactivity of two nitrosated isomers.
作者:MAKOTO MIYAHARA、MICHIKO MIYAHARA
DOI:10.1248/cpb.34.980
日期:——
1-Phenyl-3-(pyridylmethyl)ureas (I) were nitrosated with sodium nitrite under acidic conditions to give two positional isomers, 1-nitroso-1-phenyl-3-(pyridylmethyl)urea (II) and 3-nitroso-1-phenyl-3-(pyridylmethyl)urea (III). The nitrosation was carried out using several nitrosating reagents under various conditions, and each isomer was determined by means of high-performance liquid chromatography. The regioselectivity depended on the medium and reagents used. With gaseous nitrosating reagents in organic solvents at 0°C, I generated mainly III. The combination of sodium nitrite and acid (1 M perchloric acid, 1 M hydrochloric acid or 99% formic acid) gave II predominantly. However, with N2O3, the predominant product was dependent on the pH of the medium. The differences of chemical and antitumor activity of the nitroso isomers were also examined.
1-苯基-3-(吡啶甲基)脲(I)在酸性条件下与亚硝酸钠进行亚硝化反应,生成了两个位置异构体,1-亚硝基-1-苯基-3-(吡啶甲基)脲(II)和3-亚硝基-1-苯基-3-(吡啶甲基)脲(III)。亚硝化反应使用了几种亚硝化试剂在不同条件下进行,每个异构体的鉴定采用高效液相色谱法。区域选择性依赖于所用的介质和试剂。在0°C下,使用气体亚硝化试剂在有机溶剂中,I主要生成III。亚硝酸钠与酸(1 M 高氯酸、1 M 盐酸或99% 甲酸)的组合主要生成II。然而,使用N2O3时,主要产物取决于介质的pH值。此外,还考察了亚硝基异构体的化学性质和抗肿瘤活性的差异。
Reactions of 1-nitroso-1-phenyl-3-(4-pyridylmethyl)ureas.
作者:SHOZO KAMIYA、MAKOTO MIYAHARA、MICHIKO MIYAHARA
DOI:10.1248/cpb.34.385
日期:——
Treatment of 1-nitroso-1-phenyl- and 1-nitroso-1-(4-tolyl)-3-(4-pyridylmethyl)ureas (Ia, b) with methanol and ethanol at room temperature gave methyl and ethyl N-(4-pyridylmethyl)-carbamates (IIIa, b) in almost quantitative yields, together with benzene (IVa) and toluene (IVb), respectively. Treatment of Ia, b with benzene at 70°C gave 4-pyridylmethylamine (V) with biphenyl (VIa) and its 4-methyl derivative (VIb), respectively. Treatment of Ia, b with sodium azide in aqueous acetone at -5°C gave 1, 3-bis(4-pyridylmethyl)urea (VII) and phenylazides (VIIIa, b) in more than 90% yields.Compound Ia showed antitumor activity against rat ascites hepatoma AH13, but not against mouse lymphoid leukemia L1210. The mechanisms of these reactions and the mechanism of antitumor action of Ia are discussed
Intrinsic structural features of coordination polymers make an impact on dye selectivity
作者:Rinki Brahma、Jubaraj B. Baruah
DOI:10.1039/d1ce00481f
日期:——
dicarboxylate coordination polymers having 1-phenyl-3-((pyridin-4-yl)methyl)urea (L) as co-ligands with general formula [M2L2(dicarb)(H2O)2]n (dicarb = succinate or fumarate for M = Co and Zn; terephthalate for M = Co) were synthesised and characterised. Analysis of the supramolecular features of self-assemblies revealed that the hydrogen bonds of coordinated water and urea significantly contributed
Assemblies of salts of urea and thiourea derivatives and release of hosts from composites with calcium oxide
作者:Rinki Brahma、Jubaraj Bikash Baruah
DOI:10.1039/d2nj05412d
日期:——
comparison with the parent urea or thiourea derivatives are presented. The naphthalenederivatives showed characteristic emissions, among which the nitrate salt of naphurea showed dual emissions at 386 and 509 nm upon excitation at 335 nm. We have taken the advantage of the emissive behaviour of these compounds to deliberate the comparative release of urea derivatives from composites of calcium oxide impregnated