Novel annulated chromeno[3',2':5,6]pyrido[2,3-
d
][1,3,4]thiadiazolo[3,2-
a
] pyrimidines and chromeno[3'',2'':5',6']pyrido[2',3':4,5]pyrimido[2,1-
b
][1,3,4] thiadiazines: Synthetic approaches and antimicrobial efficiency
Novel annulated chromeno[3',2':5,6]pyrido[2,3-
d
][1,3,4]thiadiazolo[3,2-
a
] pyrimidines and chromeno[3'',2'':5',6']pyrido[2',3':4,5]pyrimido[2,1-
b
][1,3,4] thiadiazines: Synthetic approaches and antimicrobial efficiency