Patent ID: 8178670

Claim:
A method of preparing tetrahydrobiopterin, comprising: hydrolyzing diacetylbiopterin to biopterin in the presence of a base in a biphasic mixture, which comprises an aqueous phase containing water and an organic phase containing a water-immiscible organic solvent, wherein the aqueous phase has a pH of at least 10; optionally allowing the aqueous phase and the organic phase to separate after the hydrolysis of diacetylbiopterin is substantially complete and optionally collecting the aqueous phase as an aqueous mixture; and hydrogenating the biopterin in the aqueous mixture or the aqueous phase of the biphasic mixture, wherein the aqueous mixture or the aqueous phase has a pH of at least 10, to tetrahydrobiopterin in the presence of a platinum, palladium, or rhodium catalyst under a hydrogen pressure from 14 bar to 100 bar.