| Abstract
| - To develop a novel route for the scaleable synthesis of the chiral xanthine CVT-124 (1, aka. BG9719),a method for the late stage pyrimidine ring closure of the nitrogen-protected endo 2-norbornenylimidazole 3 was developed. The three-component coupling of benzylamine, 2-cyanoglycine ethylester (4), and methyl 5-norbornene-2-carboximidate hydrochloride (5) was demonstrated to achieve3 in 23−46% isolated yields. The imidazole 3 was then elaborated to construct the N-benzyl xanthine2 as a 1:1 mixture of exo and endo isomers, which were separable at this stage by chromatography.The nitrogen-protected endo xanthine 2 is a key intermediate in the synthesis of CVT-124.
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