1,3-Oxazines and Related Compounds. XIII. Reaction of Acyl Meldrum's Acids with Schiff Bases Giving 2,3-Disubstituted 5-Acyl-3,4,5,6-tetrahydro-2H-1,3-oxazine-4,6-diones and 2,3,6-Trisubstituted 2,3-Dihydro-1,3-oxazin-4-ones
The reaction of Schiff bases (2) with various acyl Meldrum's acids (1) were investigated.Refluxing of 1 and 2 in benzene caused an exchange reaction of the acetone moiety of 1 with the Schiff base moiety through the intermediate acylketenes 11 formed in s