Nucleophilic reaction of 5-amino- (1) and 6-amino-2-substituted benzoxazoles (2) with 3-ethoxy-2-cyanopropenonitrile (3) afforded the respective benzoxazolylaminomethylenemalononitriles 5 and 6. The amino derivatives 1 and 2 reacted with ethyl 3-ethoxy-2-cyanopropenoate (4) to give the corresponding esters of benzoxazolylamino-2-cyanopropenoic acid 7 and 8, respectively. The products 7 on thermal cyclization at 250-260 °C in a mixture of diphenyl ether and biphenyl afforded a mixture of angularly and linearly annelated 5-nitrile-4-oxooxazolo[4,5-f]quinoline 9 and 7-nitrile-8-oxooxazolo[5,4-g]quinoline 10; under the same conditions compounds 8 were converted into 8-nitrile-9-oxooxazolo[5,4-f]quinolines 11 and 6-nitrile-5-oxooxazolo[4,5-g]quinolines 12.
5-氨基-(1)和6-氨基-2-取代苯并噁唑(2)与3-乙氧基-2-氰基丙烯腈(3)的亲核反应得到了相应的苯并噁唑基氨基甲烯基马隆腈5和6。氨基衍生物1和2与乙酸乙酯基3-乙氧基-2-氰基丙烯酸(4)反应,分别得到苯并噁唑基氨基-2-氰基丙烯酸酯7和8。产物7在250-260°C的二苯醚和联苯的混合物中热环化,得到了混合的角环和线环化的5-腈基-4-氧基噁唑并[4,5-f]喹啉9和7-腈基-8-氧基噁唑并[5,4-g]喹啉10;在相同条件下,化合物8被转化为8-腈基-9-氧基噁唑并[5,4-f]喹啉11和6-腈基-5-氧基噁唑并[4,5-g]喹啉12。