92978-79-5Relevant academic research and scientific papers
Fused 1,3-Oxazine Derivatives. Synthesis of 2H-1,3-Oxazino-quinoxaline-2,4(3H)-diones (1-Oxaalloxazines), 2H-1,3-Oxazinoquinoline-2,4(3H)-diones(5-Deaza-1-oxaalloxazines), and 2H-pyrido-1,3-oxazine-2,4(3H)-diones
Yogo, Motoi,Hirota, Kosaku,Maki, Yoshifumi,Senda, Shigeo
, p. 1761 - 1769 (2007/10/02)
Reactions of 6-anilino-3-methyl-2H-1,3-oxazine-2,4(3H)-diones (1) with triethyl orthoformate, N,N-dimethylformamide dimethyl acetal, diethyl azodicarboxylate, and dimethyl acetylenedicarboxylate were carried out with the aim of synthesizing fused-ring 1,3-oxazine derivatives 3-Methyl-2H-1,3-oxazinoquinoline-2,4(3H)-dione (3-methyl-5-deaza-1-oxaalloxazine) (2) and 3-methyl-2H-1,3-oxazinoquinoxaline-2,4(3H)-dione (3-methyl-1-oxaalloxazine) (8) were obtained by the reactions of the 6-anilinooxazine (1a) with triethyl orthoformate and diethyl azodicarboxylate, respectively.Treatment of 1a with dimethyl acetylenedicarboxylate gave methyl 3-methyl-2,4,7-trioxo-8-phenyl-3,4,7,8-tetrahydro-2H-pyrido-1,3-oxazine-5-carboxylate (9a) as well as methyl 1-methyl-2,5-dioxo-1,2,5,10-tetrahydrobenzonaphthyridine-4-carboxylate (10) as a ring transformation product.The 6-(p-anisidino)-(1b) and the 6-(3,4-xylidino)-oxazine (1c) also gave the corresponding pyrido-1,3-oxazines (9b) and (9c).Keywords - 2H-1,3-oxazinoquinoxaline; 2H-1,3-oxazinoquinoline; 2H-pyrido-1,3-oxazine; benzonaphthyridine; N,N-dimethylformamide dimethyl acetal; diethyl azodicarboxylate; dimethyl acetylenedicarboxylate; ring transformation
