TY - JOUR A1 - Zhao, Long A1 - Yang, Mao-Lin A1 - Liu, Min A1 - Ding, Ming-Wu T1 - New efficient synthesis of polysubstituted 3,4-dihydroquinazolines and 4H-3,1-benzothiazines through a Passerini/Staudinger/aza-Wittig/addition/nucleophilic substitution sequence JF - Beilstein Journal of Organic Chemistry PY - 2022/// VL - 18 SP - 286 EP - 292 SN - 1860-5397 DO - 10.3762/bjoc.18.32 PB - Beilstein-Institut JA - Beilstein J. Org. Chem. UR - https://doi.org/10.3762/bjoc.18.32 KW - aza-Wittig reaction KW - 3,4-dihydroquinazoline KW - 4H-3,1-benzothiazine KW - nucleophilic substitution KW - Passerini reaction KW - Staudinger reaction N2 - A new efficient synthesis of polysubstituted 3,4-dihydroquinazolines and 4H-3,1-benzothiazines via sequential Passerini/Staudinger/aza-Wittig/addition/nucleophilic substitution reaction has been developed. The three-component Passerini reactions of 2-azidobenzaldehydes 1, benzoic acid (2), and isocyanides 3 produced the azide intermediates 4, which were treated sequentially with triphenylphosphine, isocyanates (or CS2), and secondary amines to give polysubstituted 3,4-dihydroquinazolines 8 and 4H-3,1-benzothiazines 11 in good overall yields through consecutive Passerini/Staudinger/aza-Wittig/addition/nucleophilic substitution reactions. ER -