6-(Diazomethyl)-1,3-bis(methoxymethyl)uracil, Synthesis and Transformation into Annulated Pyrimidinediones
作者:Fuyi Zhang、Anna Kulesza、Shikha Rani、Bruno Bernet、Andrea Vasella
DOI:10.1002/hlca.200890132
日期:2008.7
6-(Diazomethyl)-1,3-bis(methoxymethyl)uracil (5) was prepared from the known aldehyde 3 by hydrazone formation and oxidation. Thermolysis of 5 and deprotection gave the pyrazolo[4,3-d]pyrimidine-5,7-diones 7a and 7b. Rh2(OAc)4 catalyzed the transformation of 5 into to a 2 : 1 (Z)/(E) mixture of 1,2-diuracilylethenes 9 (67%). Heating (Z)-9 in 12n HCl at 95° led to electrocyclisation, oxidation, and
通过形成和氧化,由已知的醛3制备6-(重氮甲基)-1,3-双(甲氧基甲基)尿嘧啶(5)。热分解5和脱保护,得到吡唑并[4,3- d ]嘧啶-5,7-二酮7A和7B。Rh 2(OAc)4催化5转化为1,2-二尿嘧啶9(67%)的2:1(Z)/(E)混合物。在95°C和12n HCl中加热(Z)-9导致电环化,氧化和脱保护,得到73%的嘧啶基[5,4- f]喹唑啉四酮12。上的Rh 2(OAc)4的催化的反应5与3,4-二氢-2- ħ吡喃和2,3-二氢呋喃,得到内型/外型的2-氧杂二环的-mixtures [4.1.0]庚烷13(78% )和2-氧杂双环[3.1.0]己烷15(86%),用AlCl 3或Me 2 AlCl处理可促进乙烯基环丙烷-环戊烯的重排,从而导致吡喃和呋喃环戊[1,2- d ]嘧啶二酮14(88%)和16(51%)。同样,5的加法乘积将2-甲氧基丙烯转化为5-甲基环戊-嘧啶二酮18(55%)。5与噻吩在Rh