Sodium Sulfide → HCID 86751120, compound

Participants

Reaction Steps

Reaction Scheme 2 discloses the presently preferred method for preparing 1-N-,2'-O-dimethyl-6-thioinosine (Compound 25). In accordance with this method, adenosine (Compound 20) is reacted with methylchloride in a polar aprotic solvent, such as dimethylformamide (DMF) or dimethylacetamide (DMA) in the presence of strong base, such as sodium hydride. The resulting 2'-O-methyl adenosine is reacted, without isolation, with iodomethane to introduce the methyl group to the 1-N-position. After the treatment with iodomethane a crude product is obtained which contains approximately 60% of the desired 1-N-,2'-O-dimethyladenosine intermediate, and also contains some 1-N-,3'-O-dimethyladenosine as well as monomethylated derivatives. The crude product is reacted at a moderately elevated temperature (approximately 45° C.) with anhydrous sodium sulfide in anhydrous dimethylformamide, and the resulting crude product is purified by chromatography to yield the desired 1-N-,2'-O-dimethyl-6-thioinosine (Compound 25). ##STR7##

Provenance & Evidence