methyl (2S)-2-[(2-chloro-5-nitro-pyrimidin-4-yl)-cyclopentyl-amino]butanoate → (7S)-2-chloro-8-cyclopentyl-7-ethyl-5,7-dihydropteridin-6-one

Participants

Reaction Conditions

Reaction Steps

Methyl (2S)-2-[(2-chloro-5-nitro-pyrimidin-4-yl)-cyclopentyl-amino]butanoate 41d (14.17 g, 41.33 mmol) was dissolved in 300 mL of acetic acid followed by the addition of iron powder (9 g, 0.17 mol). After exothermic reaction was completed, the reaction solution was heated to 65° C., and stirred for 1.5 hours. The reaction mixture was filtered and the filter cake was washed with dichloromethane (350 mL). The filtrate was concentrated under reduced pressure, added with 150 mL of water and filtered. The filter cake was washed with water (60 mL×3) and the mixture solvent of hexane and acetone (V/V=6:1) (140 mL) successively. The combined organic phase was dried over anhydrous magnesium sulfate, filtered and the filtrate was concentrated under reduced pressure to obtain the title compound (7S)-2-chloro-8-cyclopentyl-7-ethyl-5,7-dihydropteridin-6-one 41e (10.67 g, yield: 92.0%) as a light yellow solid.

Provenance & Evidence