Gould-Jacobs Reaction of 5- and 6-Amino-2-substituted Benzoxazoles. I. Reaction with Diethyl Ethoxymethylenemalonate

Reaction of 2-substituted 5- and 6-aminobenzoxazoles 1 and 2 with diethyl ethoxymethylenemalonate afforded the corresponding diethyl 3- N -(5- and 6-benzoxazolyl)aminomethylenemalonates 3 and 4 . Under conditions of the Gould-Jacobs reaction, the compounds 3 gave a mixture of angularly and linearly annelated oxazolo[4,5- f ]quinolones 5 and oxazolo[5,4- g ]quinolones 6 , and compounds 4 afforded a mixture of oxazolo[5,4- f ]quinolones 7 and oxazolo[4,5- g ]quinolones 8 .