2H-1,4-Benzothiazine, the parent system of the mammalian phaeomelanic pigments, is a highly unstable molecule which readily undergoes a reversible aldolization to form, mainly, the cyclic trimer (5).
2 H -1,4-苯并
噻嗪是哺乳动物疏
蓝色素的母体系统,是一种高度不稳定的分子,易于发生可逆的醛醇缩合反应,主要形成环状三聚体(5)。