The present invention is an improved multi-step process for the production of 9-.beta.-D-arabinofuranosyl-2-fluoroadenine (2-F-AraA) and an improvement over the process of Montgomery and Hewson, J. Med. Chem., 12:498 (1969). This compound is an important tool in antitumor therapy and has shown activity against leukemia L1210 and P388 in animals as well as being a potent antiviral agent. Its therapeutic effectiveness occurs because 2-F-AraA is not a substrate for adenosine deaminase which vitiated against the activity of the parent compound 9-.beta.-D-arabinofuranosyladenine (araA) as indicated in experimental animal cancers. An advantage of making 2-F-AraA by the present process is that there is a sharply increased yield based on the chlorosugar up to about 400 percent. In the present improved process the differences lie in utilizing as a reactant 2,4,5,6-tetraaminopyrimidine; the acetylation of 2-aminoadenine in acetic acid and pyridine; the reaction of 2,6-diacetamidopurine with chlorosugar in ethylene chloride in the presence of a molecular sieve and subsequent deacetylation with methanolic sodium methoxide. Further, the diazotization step is carried out in a homogenous mixture of tetrahydrofuran and fluoboric acids. Finally, the O-benzyl groups are removed by the use of boron trichloride in ether.
本发明是一种改进的多步骤生产9-β-D-阿拉伯
核糖基-2-
氟腺嘌呤(2-F-AraA)的过程,并对Montgomery和Hewson的过程(J. Med. Chem.,12:498(1969))进行了改进。该化合物是抗肿瘤治疗的重要工具,已在动物的白血病L1210和P388中显示出活性,同时也是一种有效的抗病毒剂。其治疗效果是因为2-F-AraA不是
腺苷脱氨酶的底物,这削弱了父化合物9-β-D-阿拉伯
核糖基
腺嘌呤(araA)在实验动物癌症中的活性。使用本发明的方法制备2-F-AraA的一个优点是,基于
氯代糖,产量显著增加了约400%。在本改进的过程中,差异在于将2,4,5,6-四
氨基嘧啶作为反应物;在
乙酸和
吡啶中乙酰化2-
氨基
腺嘌呤;在存在
分子筛的
氯乙烷中,2,6-二乙酰基
嘌呤与
氯代糖反应,随后使用
甲醇钠甲醇酸盐进行脱乙酰化。此外,重氮化步骤在
四氢呋喃和
氟硼酸的均相混合物中进行。最后,使用
三氯化硼在醚中去除O-苄基基团。