Studies on the chemistry of 5-propynyloxy- and 5-propynylthiopyrimidines: New syntheses of furo- and thieno[3,2-d]pyrimidines
作者:Marianne R. Spada、Robert S. Klein、Brian A. Otter
DOI:10.1002/jhet.5570260659
日期:——
been examined. When treated with sodium methoxide in warm methyl sulfoxide, 1,3-dimethyl-5-(2-propynyloxy)uracil (6) cyclizes to afford 1,3,7-tri-methylfuro[3,2-d]pyrimidine-2,4-(1H,3H)-dione (12) in 52% yield, possibly via the allenic ether 9 (R = H). The corresponding 5-(2-butynyloxy)pyrimidine (7), obtained in good yield by treating 6 with methyl iodide and sodium hydride in methyl sulfoxide, fails
已经研究了某些5-炔基氧基-,5-炔基硫基和5-炔基亚磺酰基-嘧啶作为7-取代的呋喃[3,2- d ]-和噻吩并[3,2- d ]嘧啶的前体的用途。在温暖的亚砜中用甲醇钠处理时,1,3-二甲基-5-(2-丙炔氧基)尿嘧啶(6)环化,得到1,3,7-三甲基呋喃[3,2 - d ]嘧啶-2, 4-(1 H,3 H)-二酮(12)的产率为52%,可能通过烯丙醚9(R = H)。相应的5-(2-丁炔氧基)嘧啶(7),通过处理6获得了高收率在甲基亚砜中用甲基碘和氢化钠处理时,无法进行类似的环化反应。但是,化合物7在130°C加热时,确实会发生常规的炔基克莱森重排和环化反应,得到甲基亚砜中的8-甲基吡喃并[3,2- d ]嘧啶8和6,7-二甲基呋喃[3,2- d ]。嘧啶11的二甲基甲酰胺溶液。5-(2-丙炔硫基)嘧啶15次,得到丙二烯19和1-丙炔22当用各种碱进行处理,但没有一个-7-甲基[3,2的d