1-Bromo-2-methylpropane → 7-Benzyl-3-(2-methylpropyl)xanthine

Participants

Reaction Conditions

Reaction Steps

1.5 g (6.2 mmol) of 7-benzylxanthine from stage b) were dissolved in 50 ml of dimethylformamide at 50° C. and treated in portions with 0.149 g (6.2 mmol) of sodium hydride and stirred at 50° C. for one hour. 0.67 ml (6.2 mmol) of isobutyl bromide was added dropwise and the mixture was heated to 80° C. After 5 hours, a further 0.2 ml (1.86 mmol) of isobutyl bromide was added and the mixture was stirred for a further 5 hours. 12 ml of water and 5 ml of methanol were then added, the mixture was stirred at room temperature for 2 hours, a further 60 ml of water were added and the mixture was extracted three times using methyl tert-butyl ether. The organic phases were washed with water, dried using magnesium sulfate and concentrated under reduced pressure and the residue was purified by flash chromatography on a silica gel column, dichloromethane/methanol (99/1).

Provenance & Evidence