Benzyl Bromide → 5-hexynyluracil

Participants

Reaction Conditions

Reaction Steps

As above, 5-hexynyluracil and 6-n-butylfuranopyrimidin-2-one was prepared from 3.0 g of 5-iodouracil and 3.0 mL of 1-hexyne at 50° C. for 24 hours. Triethylamine solvent was completely distilled off at reduced pressure and a pale yellow slurry was obtained. This slurry was dissolved in 50.0 mL of DMF containing 0.70 g of KOH, and the resulting dark red solution was heated in an oil bath at 65° C. for 10 minutes. Then, 3.0 mL of benzylbromide was added to the red solution and the reaction was allowed to proceed under an Ar atmosphere until complete benzylation of 6-n-butylfuranopyrimidin-2-one to yield 1-benzyl-6-n-butylfuranopyrimidin-2-one. This alkylation took approximately 9 hours and it was monitored by TLC, as both 6-n-butylfuranopyrimidin-2-one and 1-benzyl-6-n-butylfuranopyrimidin-2-one are fluorescent under UV light but have significantly different Rf values in various solvent systems including EtOAc MeOH/Hexanes:10/1/4 and EtOAc/Ether:2/1. Once the alkylation was complete, DMF solvent was distilled off under reduced pressure and 50.0 mL of dry acetone was added to the resulting slurry to precipitate potassium bromide that was removed by gravity filtration. The filtrate was evaporated to a dark red viscous oil that was dissolved in 40.0 mL of chloroform and extraction was performed with 5% aqueous solution of EDTA (sodium salt) 2×40.0 mL and then once with 40.0 mL of distilled water.

Provenance & Evidence