Efficient synthesis of benzothieno[3,2-<i>d</i>]-imidazo[1,2-<i>a</i>]pyrimidine-2,5-(1<i>H</i>, 3<i>H</i>)-diones<i>via</i>a tandem aza-wittig/heterocumulene-mediated annulation
作者:Sheng-Zhen Xu、Jing Wu、Min-Hui Cao、Ming-Wu Ding
DOI:10.1002/jhet.258
日期:——
Carbodiimide , obtained from aza-Wittig reaction of iminophosphorane with aromaic isocyanate, reacted with α-amino ester in the presence of catalytic amount of sodium ethoxide to give selectively new tetracyclic benzothieno[3,2-d]-imidazo[1,2-a]pyrimidine-2,5-(1H, 3H)-diones in good yields. X-Ray structure analysis of verified the proposed structure and the reaction selectivity. J. Heterocyclic Chem
New Efficient Synthesis of 2-Substituted Benzothieno[3,2-<i>d</i>]pyrimidin-4(3<i>H</i>)-ones via a Tandem Aza-Wittig Reaction
作者:Ming-Wu Ding、Sheng-Zhen Xu、Yang-Gen Hu
DOI:10.1055/s-2006-950364
日期:——
with aryl isocyanates, reacted with secondary amines, phenols, or alkanols in the presence of a catalytic amount of potassium carbonate or sodium alkoxide to give 2-substituted benzothieno[3,2-d]pyrimidin-4(3H)-ones 6 in good yields. The reaction of carbodiimides 4 with primary amines RNH 2 (R ≠ H, Me) in the presence of sodium ethoxide selectively produced one regioisomer 8 via a base-catalyzed cyclization
Efficient synthesis of benzothieno[3,2-<i>d</i>]-1,2,4-triazolo [1,5-<i>a</i>]pyrimidin-5(1<i>H</i>)-ones<i>via</i>a tandem aza-Wittig/heterocumulene-mediated annulation
with hydrazine to give selectively 3-amino-2-arylaminobenzothieno[3,2-d]pyrimidin-4(3H)-ones . Reactions of with triphenylphosphine, hexachloroethane, and Et3N produced iminophosphoranes . A tandemaza-Wittig reaction of iminophosphorane with isocyanate, acyl chloride generated benzothieno[3,2-d]-1,2,4-triazolo[1,5-a]pyrimidin-5(1H)-ones and in satisfactory yields. The effects of the nucleophiles on
碳二亚胺 ,由亚氨基磷烷反应制得 与异氰酸酯反应,与肼反应,选择性地生成3-氨基-2-芳基氨基苯并噻吩并[3,2- d ]嘧啶-4(3 H)-ones。的反应与三苯膦,六氯乙烷和Et 3 N生成的亚氨基正膦。亚氨基磷烷的串联氮杂-维蒂希反应与异氰酸酯一起生成酰氯,生成苯并噻吩并[3,2- d ] -1,2,4-三唑并[1,5- a ]嘧啶-5(1 H)-ones 和 产量令人满意。已经研究了亲核试剂对环化的影响。J.杂环化学,(2009)。