Efficient One-Pot Synthesis of N-Substituted 2-Aminochromones, Their Benzo-Fused Derivatives, and Diaminobenzodipyrandiones of Two New Structural Classes

N-Substituted 2-aminochromones and their benzo-fused derivatives were obtained in high yields by a new one-pot synthesis, starting from the appropriate acetamides, salicylic acid or its benzofused derivatives, and phosphoryl chloride. By the same reaction, from suitable dihydroxybenzenedicarboxylic acids, some compounds of two new structural classes, 2,7-diaminobenzo[1,2-b:4,5b']dipyran-4,9-diones and 2,8-diamino-4H,6H-benzo[1,2-b:5,4-b']dipyran-4,6-diones, were synthesized.