Synthesis of [1,2,4]Oxadiazolo[4,5-a]thiazolo[2,3-b]pyrimidin-9(10H)-ones via 1,3-Dipolar Cycloaddition of Nitrile Oxide to Thiazolo[3,2-a]pyrimidin-3-one Derivatives
作者:Xiaofang Li、Aiting Zheng、Bin Liu、Xianyong Yu、Pinggui Yi
DOI:10.1002/cjoc.201090181
日期:——
A new class of [1,2,4]oxadiazolo[4,5‐a]thiazolo[2,3‐b]pyrimidin‐9(10H)‐one was prepared in moderate yields by the reaction of nitrileoxide with 2‐arylmethylidene‐6,7‐dihydro‐5H‐thiazolo[3,2‐a]pyrimidin‐3‐one. The reaction site of dipolarphile is the CN of thiazolo[3,2‐a]pyrimidin‐3‐one rather than the expected CC of arylmethylidene. The structures of the products were characterized thoroughly by
通过一氧化二氮与2-的反应制备了中等收率的新型[1,2,4]恶二唑并[4,5- a ]噻唑并[2,3 - b ]嘧啶9(10 H)-一亚苄基-6,7-二氢-5- ħ -噻唑并[3,2-一个]嘧啶-3-酮。偶极亲核试剂的反应位点是噻唑[3,2 - a ]嘧啶-3-酮的CN,而不是芳基亚甲基的预期CC。通过IR,元素分析,MS和NMR分析对产物的结构进行了彻底的表征。
Unexpected nitrilimine cycloaddition of thiazolo[3,2-a]pyrimidine derivatives
1,3-Dipolarcycloaddition of 2-arylidene-6,7-dihydro-5H-thiazolo[3,2-a]pyrimidine-3(5H)-ones to diphenylnitrilimine (generated in situ by triethylamine dehydrohalogenation of the N′-phenylbenzohydrazonoyl chloride) proceeded regio- and site-selectively affording a mixture of two unexpected isomer products at reflux temperature. The cycloaddition/ring-opening/rearrangement/substitution, mechanism of
2-芳基-6,7-二氢-5 H-噻唑并[3,2- a ]嘧啶-3(5 H)-ones的1,3-偶极环加成反应成二苯基硝胺(通过N '的三乙胺脱卤作用原位生成) -苯基苯并偶氮酰氯)在回流温度下进行区域和位点选择性反应,得到两种意想不到的异构体产物的混合物。还讨论了环加成/开环/重排/取代反应的机理。
Synthesis of Spiro Thiazolo[3,2-<i>a</i>]Pyrimidine-Tetrahydrothiophenes <i>via</i> Sulfa-Michael/Aldol Cascade Reactions
作者:Jinlong Yan、Xinliang Fu、Wei Li
DOI:10.3184/174751917x15125690124282
日期:2017.12
The sulfa-Michael/aldol cascade reaction of 2-arylmethylidene-6,7-dihydro-2H-thiazolo[3,2-a]pyrimidin-3(5H)-ones and 1,4-dithiane-2,5-diol afforded novel 2′-aryl-4′-hydroxy-4′,5′,6,7-tetrahydro-2′H-spiro[thiazolo[3,2-a]pyrimidine-2,3′-thiophen]-3(5H)-ones in good yields. The structures of all products were characterised thoroughly by NMR, IR, HRMS, together with X-ray crystallographic analysis.