Sodium triacetoxyborohydride → (+/-)-{2-[1-(3-Benzyl-7-chloro-4-oxo-3,4-dihydro-pteridin-2-yl)-2-methyl-propylamino]-1,1-dimethyl-ethyl}-carbamic acid tert-butyl ester

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Reaction Steps

Formula 201 where R2 is H; R3 is Cl; R5 is Benzyl; R6 is Isopropyl; R6′ is H; Ra and Rb are Methyl; W and Z are —N═; X and Y are —C═: To a solution of 2-(1-amino-2-methyl-propyl)-3-benzyl-7-chloro-3H-pteridin-4-one (1.10 g, 3.19 mmol) and (1,1-dimethyl-2-oxo-ethyl)-carbamic acid tert-butyl ester (Seki et. al. Chem. Pharm. Bull. 1996, 44, 2061) (0.59 g, 3.19 mmol) in dichloromethane (80 mL) is added sodium triacetoxyborohydride (1.01 g, 4.79 mmol). The resultant mixture is maintained at ambient temperature for 4 hours, at which time it is quenched with brine (75 mL) and stirred vigorously for 10 minutes. The aqueous layer is extracted with dichloromethane (50 mL) and the combined extracts are dried over magnesium sulfate, filtered and concentrated under reduced pressure to give (±)-{2-[1-(3-benzyl-7-chloro-4-oxo-3,4-dihydro-pteridin-2-yl)-2-methyl-propylamino]-1,1-dimethyl-ethyl}-carbamic acid tert-butyl ester which is used in the subsequent step without purification.

Provenance & Evidence