Patents Glaxo-Wellcome

Figure 3.3.18 Microphotographs of Forms 1 and 2 of the antiulcer drug ranitidine hydrochloride produced by Glaxo Wellcome (now Glaxo Smith Kline). The differences in physical form of the crystals lead to differences in filtering and drying characteristics, which were among the improvements over Form 1 noted in the Form 2 patent application.

More recently, Glaxo Wellcome have disclosed in the patent literature... 

An interesting variation of the method was patented by Glaxo Wellcome Inc [146]. Their synthesis was started from 2,4-dichloro-5-fluoropyrimidine (93) (Scheme 38). Reaction of 93 with NaOEt and then - with anion of 2,2-dimethoxyethanol gave pyrimidine derivative 163, which upon detection formed aldehyde 164. Reaction of 164 and 154 led to the formation of 1,3-oxa-thiolane 165, which was acetylated to give 166. Treatment of 166 with TMSOTf resulted in rearrangement leading to 167, which was transformed to racemic 8 (Racivir) by reaction with ammonia. 

Scheme 38 Synthesis of racemic 8 (Racivir) patented by Glaxo Wellcome Inc. (Relative configurations are shown)...

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