A highly efficient and green protocol for the synthesis of pyrimido[4,5- b ]quinolines has been described. The one-pot multicomponent reaction of dimedone with arylaldehydes and 6-amino-1,3-dimethyluracil in the presence of N,N- diethyl- N -sulfoethanaminium chloride ([Et 3 N–SO 3 H][Cl]) as an ionic liquid (IL) catalyst under solvent-free conditions afforded the mentioned compounds in high yields and short reaction times. Our protocol is superior to many of the reported protocols in terms of two or more of these factors: the reaction times, yields, conditions (solvent-free versus usage of organic solvents), temperature and catalyst amount.

中文翻译：

---

N，N-二乙基-N-磺基硫代氯化铵合成嘧啶并[4,5-b]喹啉的高效绿色方法

已经描述了用于合成嘧啶并[4，5-b]喹啉的高效和绿色方案。在N，N-二乙基-N-磺基氨基钛氯化铵（[Et 3 N–SO 3 H] [Cl]）存在下，二甲酮与芳醛和6-氨基-1,3-二甲基尿嘧啶的一锅多组分反应离子液体（IL）催化剂在无溶剂条件下以高收率和较短的反应时间提供了上述化合物。在以下两个或多个因素方面，我们的方案优于许多已报道的方案：反应时间，收率，条件（无溶剂与有机溶剂的使用），温度和催化剂用量。