A facile transformation of 2-aminochromone to 4-chlorocoumarin and its reaction with ethylenediamine

2-Aminochromones 1a–c and 8a–c are converted into 4-chlorocoumarins 2a–c and 9a–c. On treatment with ethylenediamine, 2a–c produce 2,3,4,5-tetrahydro-7-(2′-hydroxyphenyl)-1,4-diazepin-5-one 3a,b and 4-(2-aminoethyl) aminocoumarin 4b,c in ethanol; while in DMF 9a–c give the bis[4-(2-formamidoethyl)aminocoumarins 10a–c.