A Novel and Efficient Synthesis of 4<i>H</i>-3,1-Benzoxazines by a Tandem Aza-Wittig/Heterocumulene-Mediated Annulation Strategy
作者:Pedro Molina、Antonio Arques、Angel Molina
DOI:10.1055/s-1991-26368
日期:——
2-[(Triphenylphosphoranylidene)amino]benzyl alcohol 2 reacts with isocyanates or isothiocyanates in refluxing toluene to give the corresponding 2-alkyl(aryl)amino-4H-3,1-benzoxazines 5. Iminophosphorane 2 also reacts with carbon dioxide and carbon disulfide to give 4H-3,1-benzoxazin-2(1H)-one (6) and -thione (7), respectively.