Fused Thiazoles from 3-Amino-2-thioxo-2,3-dihydrothiazoles: Synthesis of Mesoionic Thiazolo[2,3-b]-1,3,4-thiadiazoles and 2,3-Dihydro-4H-thiazolo[2,3-b][1,3,4]thiadiazin-5-ium Derivatives - Molina, P; Arques, A; Velasco, M D; Villalgordo, J M (Synthesis, 1988)