trans-Stereoselective Reduction of Hexahydroquinazoline-2(1H)-thione Derivatives
摘要:
Reduction of substituted 4-arylhexahydroquinazoline-2(1H)-thiones using NaBH4/CF3CO2H in chloroform gave the corresponding trans-fused octahydroquinazoline-2(1H)-thiones. The use of two reducing systems, NaBH4/CH3CO2H or NaBH4/CF3CO2H, permitted the consecutive trans-selective reduction of the endo- and exocyclic double bond in the case of 8-dithiomethylidene derivatives of hexahydroquinazoline-2(1H)-thiones.
An efficient one‐pot method for synthesis of new biologically active thiazolo[3,2‐a]pyrimidine and thiazolo[2,3‐b]quinazoline derivatives is described via reaction of pentachloropyridine with fused pyrimidine‐2(5H)‐thiones or quinazoline‐2(1H)‐thiones. These reactions were carried out in the presence of potassium carbonate as a base in acetonitrile as a solvent to produce products 3a–n in good‐to‐excellent
通过五氯吡啶与稠合的嘧啶-2(5 H)-硫酮的反应,描述了一种有效的一锅法合成新的生物活性噻唑并[3,2- a ]嘧啶和噻唑并[2,3- b ]喹唑啉衍生物。喹唑啉-2(1 H)-硫酮。这些反应是在乙腈作为溶剂的碳酸钾作为碱存在下进行的,从而以良好至优异的产率生产出3a - n产物。五氯吡啶是形成环环状噻唑并[3,2- a ]嘧啶和噻唑并[2,3- b ]喹唑啉产物的双重亲电基石。