Patent ID: 6693193
Filing Date: 2004-02-17
Classification: A61P,C07D,C07H,Y02P

Abstract:
A process of preparing a compound of the formula wherein B is chosen from OH, NH2, NHR, H or halogen; D is chosen from OH, NH2, NHR, H, halogen or SCH3; R is an optionally substituted alkyl, aralkyl or aryl group; and Z is selected from OH, hydrogen, halogen, hydroxy, SQ or OQ, Q is an optionally substituted alkyl, aralkyl or aryl group; or a tautomer thereof; or a pharmaceutically acceptable salt thereof; wherein the process comprises the following steps:(a) reacting a compound of the formula (II) â€ƒwherein Zâ€² is a hydrogen or halogen atom, a group of formula SQ or OQ, or a trialkylsilyloxy, alkyldiarylsilyloxy or optionally substituted triarylmethoxy group and Q is an optionally substituted alkyl, aralkyl or aryl group, sequentially with a halogenating agent and a base to form an imine; (b) condensing the imine thus prepared with an anion produced by abstraction of the bromine or iodine atom from a compound of formula (XIX): â€ƒwherein R5 is a bromine or iodine atom, R6 is an N-protecting group, Bâ€² and Dâ€² are independently selected from H, OR7 and N(R8)2, and R7 and R8 are O- and N-protecting groups respectively to produce a 1-C-(pyrrolo[3,2-d]pyrimidin-7-yl)-1,4-dideoxy-1,4-imino-2,3-O-isopropylidene-D-ribitol derivative of formula (XX): â€ƒwherein R9 is a hydrogen atom, Zâ€² is as defined above for compounds of formula (II) and R6, Bâ€² and Dâ€² are as defined above for compounds of formula (XIX); (c) optionally, converting the compound of formula (XX) to a compound of formula (XX) where Zâ€², R6, Bâ€² and Dâ€² are as defined above but R9 is alkoxycarbonyl or aralkoxycarbonyl, or, optionally, where Zâ€² in the compound of formula (XX) is trialkylsilyloxy, alkyldiarylsilyloxy or optionally substituted triarylmethoxy, converting the compound of formula (XX) to a compound of formula (XX) wherein R6, R9, Bâ€² and Dâ€² are as defined above but Zâ€² is OH; and (d) N- and O-deprotecting the compound of formula (XX) prepared from step (b) or (c) by acid- or alkali-catalyzed hydrolysis or alcoholysis or catalytic hydrogenolysis as required for the O- and N-protecting groups in use, to produce a compound of the formula (I) as defined above.