Preparation of Imidazolidin-4-ones and Their Evaluation as Hydrolytically Cleavable Precursors for the Slow Release of Bioactive Volatile Carbonyl Derivatives
作者:Alain Trachsel、Barbara Buchs、Guillaume Godin、Aurélien Crochet、Katharina M. Fromm、Andreas Herrmann
DOI:10.1002/ejoc.201200081
日期:2012.5
Imidazolidin-4-ones are suitable in practical applications as hydrolytically cleavable precursors for the controlled release of fragrant aldehydes and ketones. The corresponding profragrances were prepared by treating aliphatic carbonyl compounds with commercially available amino acid amines in the presence of a base to yield mixtures of diastereomers. The two diastereomers isolated from the reaction
Imidazolidin-4-ones 适用于实际应用中作为可水解裂解的前体,用于控制释放芳香醛和酮。通过在碱存在下用市售氨基酸胺处理脂肪族羰基化合物以产生非对映异构体的混合物来制备相应的前体香料。从甘氨酰胺盐酸盐与 (-)-薄荷酮反应中分离的两种非对映异构体通过柱色谱分离。异构体的绝对立体化学由核磁共振光谱确定,并由 X 射线单晶结构分析证实。在酸性条件下和质子溶剂中,两种非对映异构体缓慢异构化而不释放酮。通过从缓冲水溶液和阳离子表面活性剂乳液中的溶剂萃取以及沉积到棉花表面后的动态顶空分析来研究前体的水解。一般来说,酮类比醛类更容易释放。增加 C-5 处取代基的大小会降低溶液中和棉花表面的水解速度。基于甘氨酰胺的 imidazolidin-4-ones 比相应的 oxazolidin-4-ones 或 oxazolidines 更有效。溶液中的释放速率、前体结构的疏水性(影响沉积)以及这