4ⴕ,x-Seco and 4ⴕ,x-4ⴕ,5ⴕ-Diseco C-Nucleosides from 2-Hydrazino-(3H)- thieno[2,3-d]pyrimidin-4-ones
Atef A. Hamed
a, Hesham F. Bader
a, and El-Sayed H. El-Ashry
ba Department of Chemistry, Faculty of Science, Menoufia University, Shebin El-Koam, Egypt
b Department of Chemistry, Faculty of Science, Alexandria University, Alexandria, Egypt Reprint requests to Prof. Dr. E. S. H. El Ashry.
Fax: +20-3-4271360. E-mail: eelashry@link.net
Dedicated to Prof. Dr. I. F. Zeid on the occasion of his 60thbirthday Z. Naturforsch.56 b, 826Ð836 (2001); received January 18, 2001
Thieno[2,3-d]pyrimidinone, Triazolo[3,4-a]thieno[2,3-d] pyrimidinone, Sugar Hydrazones Cyclization of 2-hydrazino-5,6-dimethyl-3H-thieno[2,3-d]pyrimidin-4-one (1) with acetic acid gave 3,6,7-trimethyl-1,2,4-triazolo[3,4-a]thieno[2,3-d] pyrimidin-5-one (5) whose Dim- roth rearrangement gave 2,6,7-trimethyl-1,2,4-triazolo[3,4-a]thieno[2,3-d]pyrimidin-5-one (11). Alternatively,5was obtained from the dehydrogenative cyclization of acetaldehyde 5,6- dimethyl-4-3H-oxo-thieno[2,3-d]pyrimidin-2-yl hydrazone (7). Reaction of1 and 2 with a number of sugars gave the respective hydrazones19and20. Those of the D-glucose exist in the cyclic pyranosyl structure in addition to minor amounts of the acyclic structure. Dehydro- genative cyclization of the sugar hydrazones gave the respective fused tricyclic compounds 25and26.
