Reaction of 6-arylamino-1,3-dialkyluracils with anhydrides of polyfluorocarboxylic acids in the presence of pyridine and subsequent cyclization with concentrated H2SO4 gave the corresponding 1,3-dialkyl-5-(polyfluoroalkyl)pyrimido[4,5-b]quinoline-2,4(1H,3H)-diones (5-polyfluoroalkyl-5-deazaalloxazines). The reactivity of these compounds towards nucleophilic reagents, such as sodium cyanoborohydride, acetophenone, nitromethane, potassium cyanide, indole and p-thiocresol, as well as Suzuki and Sonogashira couplings are described. The nucleophilic addition takes place at the 5-position of the 5-deazaalloxazine system and is in many cases irreversible to give 5,10-dihydropyrimido[4,5-b]quinoline-2,4(1H,3H)-dione derivatives in good to excellent yields.
6-芳基
氨基-1,3-双烷基尿
嘧啶与多
氟羧酸的酐在
吡啶存在下反应,并随后与浓
硫酸环化,生成相应的1,3-双烷基-5-(多氟烷基)pyrimido[4,5-b]
喹啉-2,4(1H,3H)-二酮(5-多氟烷基-5-去氮
氨基尿
嘧啶)。这些化合物对亲核试剂的反应性进行了描述,包括
氰硼氢
钠、
乙酰苯、亚
硝基甲烷、
氰化钾、
吲哚和对
硫甲
酚,以及铃木和园和尚反应。亲核加成发生在5-去氮
氨基尿
嘧啶体系的5位,在许多情况下是不可逆的,生成5,10-二氢pyrimido[4,5-b]
喹啉-2,4(1H,3H)-二酮衍
生物,产率良好至优异。