A synthesis of amidine derivatives, 4-alkyl[aryl]amino-2,5-dihydro-2,2,5,5-tetramethylimidazol-1-yl oxides is described. The first step is a 1,3-dipolar cycloaddition of 2,5-dihydro-2,2,5,5-tetramethylimidazol-1-yl 1,3-dioxide with isocyanates or diisocyanates. Alkaline hydrolysis of the resulting 3-substituted 2,3,3a,4,5,6-hexahydro-4,4,6,6-tetramethyl-2-oxoimidazo[1,5-b][1,2,4]oxadiazol-5-yl oxides affords the corresponding amidines. The resulting spin probes and labels may be used for measuring the local pH values in the range 3.3-7.8 in biological systems.
报道了一种合成脒类衍
生物的方法,即4-烷基[芳基]
氨基-2,5-二氢-2,2,5,5-四甲基
咪唑-1-基氧化物。第一步是以2,5-二氢-2,2,5,5-四甲基
咪唑-1-基-1,3-二氧化物与
异氰酸酯或二
异氰酸酯进行1,3-偶极环加成反应。随后通过碱性
水解得到的3-取代的2,3,3a,4,5,6-六氢-4,4,6,6-四甲基-2-氧代
咪唑并[1,5-b][1,2,4]氧二唑-5-基氧化物,可以得到相应的脒。由此制备的自旋探针和标记物可用于测定
生物系统中3.3至7.8范围内的局部pH值。