Synthesis of Benzoxazinones
Solvent-assisted grinding enables a mild and convenient synthesis of 2-substituted 4H-3,1-benzoxazin-4-ones, 2-aminobenzoxazin-4-ones, and 2-amino-4H-3,1-benzothiazin-4-ones from N-substituted anthranilic acid derivatives in the presence of 2,4,6-trichloro-1,3,5-triazine and catalytic triphenylphosphine via a rapid cyclodehydration.
M. Pattarawarapan, S. Wet-osot, D. Yamano, W. Phakhodee, Synlett, 2017, 28, 589-592.
A facile and efficient copper-catalyzed method for the synthesis of 4H-3,1-benzoxazin-4-one derivatives is based on a tandem intramolecular C-N coupling/rearrangement process. This method provides a new and useful strategy for construction of N-heterocycles.
Z.-Y. Ge, Q.-M. Xu, X.-D. Fei, T. Tang, Y.-M. Zhu, S.-J. Ji, J. Org. Chem., 2013, 78, 4524-4529.
A series of substituted benzoxazinones were synthesized from N-(o-bromoaryl)amides by palladium-catalyzed carbonylation with paraformaldehyde as the carbonyl source, which is inexpensive, stable, and easy to use.
W. Li, X.-F. Wu, J. Org. Chem., 2014, 79, 10410-10416.