PURINES .46. PREPARATION OF 1-ETHYLADENINE FROM ADENOSINE

A detailed account is given of the synthesis and glycosidic cleavage of 1-ethyladenosine (2b), which established an alternative synthesis of 1-ethyladenine (3b). Ethylation of adenosine (1) with EtI in AcNMe2 at 35-38-degrees-C for 90 h gave 2b. HI in 54% yield. The hydriodide 2b. HI was readily converted into the perchlorate 2b. HClO4 and into the free nucleoside 2b. Treatment of 2b. HI with 0.5 N aqueous HCl at 92-94-degrees-C for 30 min or that of 2b. HClO4 with boiling AcOH for 60 min produced the aglycone 3b in good yield. The free base easily formed the hydrochloride 3b. HCl, and the perchlorate 3b. HClO4 as well.