Synthesis of 6-Membered-Ring Fused Thiazine-Dicarboxylates and Thiazole-Pyrimidines via One-Pot Three-Component Reactions

• Published in: Molecules (Basel, Switzerland) Vol. 26; no. 18; p. 5493
• Main Authors: Mohlala, Reagan L, Coyanis, Elena Mabel, Fish, Muhammad Q, Fernandes, Manuel A, Bode, Moira L
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 10.09.2021; MDPI
• Subjects: dialkyl acetylenedicarboxylates; Investigations; isocyanides; multicomponent reaction; Pyrimidines; thiazine; thiourea; α-haloketone; isocyanides; thiourea; dialkyl acetylenedicarboxylates; thiazole-pyrimidines; multicomponent reaction; α-haloketone; thiazine
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules26185493

A facile and efficient one-pot three-component reaction method for the synthesis of thiazine-dicarboxylates is reported. Reaction of an isocyanide and dialkyl acetylenedicarboxylate with 2-amino-4 -1,3-thiazin-4-one derivatives containing both an acidic proton and an internal nucleophile gave the products in good yields of 76-85%. The reactivity of dialkyl acetylenedicarboxylates was further tested in the synthesis of thiazole-pyrimidines where a two-component reaction of 2-aminothiazole with dialkyl acetylenedicarboxylates was successfully converted to a more efficient three-component reaction of a thiourea, α-haloketone and dialkyl acetylenedicarboxylate (DMAD/DEtAD) to give thiazole-pyrimidines in good yields of 70-91%.