Chloride → 5-Ethyl-1-(3-acetoxypropyloxymethyl)-6-(3,5-dimethylbenzyl)uracil

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a suspension of 5-ethyl-6-(3,5-dimethylbenzyl)uracil (645 mg, 5 mmol) (prepared as described for the preparation of 6-(3,5-dimethylbenzyl)-5-isopropyluracil in the above Example 1-A but in replacing the 2-bromo-3-methylbutanoic acid by the 2-bromobutanoic acid) and 1-acetoxy-3-acetoxymethoxypropane (prepared as described in the above Example 1-B) (950 mg, 5 mmol) in ethanenitrile (25 ml), were added hexamethyldisilazane (810 mg, 5 mmol) and chlorotrimethylsilane (545 mg, 5 mmol). After 10 minutes under stirring at 20° C., it was added dropwise thereto, in 10 minutes, a solution of tinIV chloride (782 mg, 2.4 mmol) in ethanenitrile (7 ml). After 14 h under stirring, it was added to the reaction medium dichloromethane (70 ml) and an aqueous saturated sodium hydrogenocarbonate solution (70 ml). The organic phase was separated by decantation and the aqueous phase was extracted with dichloromethane (3×50 ml). The collected organic phases were washed with saturated sodium hydrogenocarbonate solution (25 ml), with water (25 ml) and with an aqueous saturated sodium chloride solution (25 ml). The organic phase was dried over sodium sulfate, concentrated, and subjected to a flash column chromatography on silica gel (ethyl acetate/petroleum ether 1:1) to give 0.85 g (87%) of 5-ethyl-1-(3-acetoxypropyloxymethyl)-6-(3,5-dimethylbenzyl)uracil.

Herkunft & Nachweise