Efficient and .BETA.-Stereoselective Synthesis of 4(5)-Methyl-5(4)-(5-amino-5-deoxy-.BETA.-D-ribofuranosyl)imidazole and Related Compounds Exhibiting Antiulcer Activity.
作者:Shinya HARUSAWA、Hideki MORIYAMA、Yoshihiko MURAI、Tomonari IMAZU、Hirofumi OHISHI、Ryuji YONEDA、Takushi KURIHARA、Hiroyoshi HATA、Yasuhiko SAKAMOTO
DOI:10.1248/cpb.45.53
日期:——
debenzylation gave 21, which was successively derived to the 5'-amino derivative 1 via the 5'-substituted phthalimide 23, followed by hydrazine degradation in excellent yield. Compound 1 was then converted into the 5'-cyanoguanidine 2 in 79% yield. The 5'-amino derivatives 3-9 lacking a methyl group were efficiently synthesized. Among them, the cyanoguanidine 5 and phenylthiourea 8 exhibited antiulcer activities
2,3,5-三-O-苄基-D-核糖与咪唑衍生物的锂盐反应,得到加合物17RS。用1.5N HCl在回流的四氢呋喃中处理17RS,得到β-4(5)-核呋喃基呋喃基咪唑19(35%)和核糖基咪唑18(51%)。通过Mitsunobu环化将后者转化为β-19,产率为86%。该合成方法仅产生所需的β-端基异构体。用乙氧基羰基保护19的咪唑氮,然后脱苄基化,得到21,其通过5'-取代的邻苯二甲酰亚胺23连续衍生为5'-氨基衍生物1,然后肼以优异的产率降解。然后将化合物1以79%的产率转化为5'-氰基胍2。有效地合成了缺少甲基的5'-氨基衍生物3-9。其中,氰基胍5和苯硫脲8的抗溃疡活性为西咪替丁的一半。通过X射线结构分析确定5的分子构象。