| Popis: |
2-Tosyl-1,2,3,12b-tetrahydroimidazo[1,5-f]lphenanthridine ( 6 ) was prepared in five steps from 6-chloromethylphenanthridine ( 1 ) in an overall yield of 50%. The reaction of 6 with 1,3-dimethyl-6-methylaminouracll ( 8 ) in CH 3 CN/TFA (100:1) at 50-80°C, gave a mixture of products from which 1,3-dimethyl-6-methylaminothymine ( 9a ) could be isolated. This constitutes a mimic of the overall dTMP synthase reaction in transferring both a methylene unit and a hydride equivalent from the cofactor model 6 to the 5-position of a uracil derivative. The other products which are formed in the reaction of 6 with 8 are derived from the reaction of the exocyclic intermediate C , formed in the carbon transfer step, with nucleophiles present in the reaction mixture. |
