1,X-二甲基咔唑的一种形成机理

A POSSIBLE GENETIC MECHANISM OF 1,X-DIMETHYLCARBAZOLES

通过对珠江口盆地原油中性含氮化合物的分析发现,1,3-二甲基咔唑(DMC)与1,6-二甲基咔唑(DMC)的比值表现出惊人的不变性(≈1),而与二者本身在原油中的绝对浓度无关。这一特征可能揭示了:1,3-DMC和1,6-DMC具有共同的前身物——1-甲基咔唑;1,3-DMC和1,6-DMC都是通过1-甲基咔唑由3、6环碳位上的甲基化作用形成的。相对于1,3-DMC和1,6-DMC而言,1,4-DMC和1,5-DMC显示出相当一致的变化趋势,表明了在1-甲基咔唑进一步的甲基化中,3、6与4、5环碳位上存在竞争性反应过程。

The analyses of alkylcarbazoles in the oils from the Pearl River Mouth Basin show that the ratio of 1,3-dimethylcarbazole (DMC) to 1,6-DMC displays a remarkable invariance (about 1) independent of their absolute concentrations. This may indicate that 1,3- and 1,6-DMC had a common precursor: 1-methylcarbazole. The formation of 1,3- and 1,6-DMC resulted from methylation at ring carbon 3 and 6, which have identical reaction activities, in 1-methylcarbazole in kerogen matrix with identical rate. The 1,4- and 1,5-DMC contents display quite uniform variance trends as that of 1,3- and 1,6-DMCs in the oils, which indicated during the methylation of 1-methylcarbazole a competitive reaction occurred between ring carbon 3, 6 and ring carbon 4, 5 in 1-methylcarbazole.