939125-18-5Relevant articles and documents
A new synthesis of pteridines substituted with branched and linear alkenyl groups at C(6). The nitroso-ene reaction of 4-(alkenoylamino)-5- nitrosopyrimidines
Zhang, Fang-Li,Schweizer, W. Bernd,Xu, Ming,Vasella, Andrea
, p. 521 - 534 (2008/02/07)
Pteridines substituted with a 1,1-, 1,2-, or 1,1,3-substituted alkenyl group (mostly (is)-configured) at C(6) were synthesized in high yields by the intramolecular nitroso-ene reaction of 4-(alkenoylamino)-2-amino-6-benzyloxy-5- nitroso- and 4-(alkenoylamino)-2,6-diamino-5-nitrosopyrimidines. Thus, the N-alkenoyl nitrosopyrimidines 4 and 5 provided the pteridines 6 and 7, respectively, characterized by a 1,2-disubstituted (E)-alkenyl substituent, the C(4)-(E)-geranoyl amide 13 led regio- and stereoselectively to the (E)-1,1,2-trisubstituted alkenyl-pteridine 16, and the C(4)-(Z) isomer 14 led to 17 possessing a 1,1-disubstituted alkenyl group. The trifluoromethylated butenoyl amide 15 possessing a less highly nucleophilic alkenoyl group reacted more slowly to give the trifluoromethylated vinylpteridine 18. Also the 4-(alkenoylamino)-2,6-diamino-5-nitrosopyrimidine 20 reacted more slowly than 4 and 5, and provided the pteridines 23; introduction of additional N-acyl groups as in 21 and 22 led to a considerably faster ene reaction. The X-ray crystal structure analysis of the nitroso amide 15 shows eight symmetrically independent molecules in the unit cell. In the crystalline state, the N,N- dimethylformamidine derivative 9 of 6 forms a centrosymmetric dimer with the 7,8-lactam group connected by intermolecular hydrogen bonds.
