Sonogashira cross-coupling of 6-chloro-1,3-dimethyllumazine with terminal alkynes gave 6-alkynyl derivatives in good yields. Oxidative amination of the latter with primary alkylamines was accompanied by the pyrrole-ring closure to form 1-R'-2-R-6,8-dimethylpyrrolo[3,2-g]pteridine-5,7(6H,8H)-diones. The addition of bromine to 6-alkynyllumazines afforded the corresponding dibromoalkenes whose treatment with sodium trithiocarbonate gave rise to 2-R-6,8-dimethyltliieno[3,2-g]pteridine-5,7(6H,8H)-diones. The latter compounds are close analogs of the metabolite of molybdenum cofactor (molybdopterine).
Synthesis and heterocyclizations of 3-alkynyl-6,8-dimethylpyrimido-[4,5-<i>c</i>]pyridazine-5,7(6<i>H</i>,8<i>H</i>)-diones and their lumazine analogues
作者:Anna V. Gulevskaya、Shee Van Dang、Alexander F. Pozharskii
DOI:10.1002/jhet.5570420308
日期:2005.4
Synthesis of some condensed pyrrolo-, thieno-, furo-, pyrido- and pyranopteridines as well as isomeric pyrrolo- and thienopyrimido[4,5-c]pyridazines from alkynyl derivatives of 6,8-dimethylpyrimido[4,5-c]pyridazine-5,7(6H,8H)-dione and 1,3-dimethyllumazine is represented.
由6,8-二甲基嘧啶并[4,5- c ]哒嗪的炔基衍生物合成一些稠合的吡咯并,噻吩并,呋喃基,吡啶并和吡喃蝶啶以及异构体吡咯并和噻吩并嘧啶并[4,5 - c ]哒嗪。代表-5,7(6 H,8 H)-二酮和1,3-二甲基鲁嗪。