反应详情

15 g of 7-(5-oxohexyl)-1,3-dimethylxanthine are dissolved in 100 ml of ethanol and mixed portionwise at room temperature with 3.8 g of sodium borohydride (110% of theory) in solid form or in alcoholic suspension. At the end of addition stirring takes place for 30 minutes. Subsequently heating takes place to boiling temperature. At this time the reaction is completed. The course of the reaction is followed by thin layer chromatography. The solvent is evaporated on a rotary evaporator. The residue is boiled e.g. with 50 ml of isopropanol or ethyl acetate. The insoluble substance is filtered off and discarded. The extract is crystallised by evaporation. 7-(5-hydroxyhexyl)-1,3-dimethylxanthine of m.p. 93° to 94° C. in a yield of 86% by weight is obtained. The substance after chromatography with silica gel F254 (Merck sheets) as the absorbent and with a mixture of benzene and acetone in a volume ratio of 60:40 as the eluting agent has a Rf -value of 0.15.

1. additionAt the end of addition
2. customfor 30 minutes
3. temperatureSubsequently heating
4. customThe solvent is evaporated on a rotary evaporator
5. filtrationThe insoluble substance is filtered off
6. customThe extract is crystallised by evaporation