Synthesis of tetrahydropteridine C6-stereoisomers, including N5-formyl-(6S)-tetrahydrofolic acid
摘要:
Chiral N1-protected vicinal diamines derived from amino acids were condensed with 2-amino-6-chloro-5-nitro-4(3H)-pyrimidinone, the nitro group reduced, and the amine deprotected. oxidative cyclization of the resulting triaminopyrimidinone via quinoid pyrimidine intermediates gave a quinoid dihydropteridine, which was then reduced to a tetrahydropteridine C6-stereoisomer. Thus, 6(R)- and 6(S)-propyltetrahydropterin were stereospecifically synthesized (99% enantiomeric purity) in good yield from D- and L-norvaline, respectively. Reductive alkylation of (p-aminobenzoyl)-L-glutamate with a nitropyrimidine aldehyde derived from D- or L-serine similarly afforded, after cyclization and reduction, (6R)- or (6S)-tetrahydrofolic acid. The latter was then converted to the natural isomer of leucovorin by regioselective N5-formylation with carbonyl diimidazole/formic acid without loss of enantiomeric purity.
PREPARATION WITH IMPROVED BIOABSORBABILITY OF SAPROPTERIN HYDROCHLORIDE
申请人:Asubio Pharma Co., Ltd.
公开号:EP1964566A1
公开(公告)日:2008-09-03
A method of significant improvement for the bioavailability of orally administered sapropterin hydrochloride, a therapeutic agent used to treat BH4-responsive hyperphenylalaninemia, is provided. Also provided is a preparation for oral administration or ingestion having an improved bioavailability of sapropterin hydrochloride. Specifically, the preparation having an improved bioavailability of sapropterin hydrochloride contains sapropterin hydrochloride and an absorption promoter including an organic carboxylic acid having more than one carboxyl group in its molecule. The organic carboxylic acid having more than one carboxyl group in its molecule is selected from tartaric acid, citric acid, malic acid and optically active substances thereof, racemic mixtures thereof, anhydrides thereof, hydrates thereof or mixtures thereof. The amount by weight of the organic carboxylic acid is 0.1 to 100 times that of sapropterin hydrochloride.