Theophylline → Methyl (S)-2-(1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-7H-purin-7-yl)propanoate

Participants

Reaction Conditions

Reaction Steps

To a suspension of 1,3-dimethyl-1H-purine-2,6(3H,7H)-dione (20 g, 111 mmol) and K2CO3 (30.6 g, 222 mmol) in DMF (400 mL) was added (R)-methyl 2-((methylsulfonyl)oxy)propanoate (which may be synthesized according to the procedure described in PCT Pub No. WO/2005/059107 (40 g, 222 mmol). The reaction mixture was stirred at 20° C. for 20 h. The reaction mixture was then quenched with saturated NH4Cl(aq), diluted with water and extracted with CH2Cl2 (3×). The combined organic extracts were washed 3× with 10% LiCl (aq), dried over Na2SO4 and evaporated in vacuo. The residue was purified using silica gel column chromatography eluting first with PE:CH2Cl2 (1:1) followed by CH2Cl2:MeOH (50:1) to give 13.5 g (50.7 mmol, 45.7%, ee: 95%) of the (S)-product. The (S)-product was analyzed by chiral HPLC to determine it is at least 95% pure as the S-isomer (≧95% ee).

Provenance & Evidence