| Abstrakt: |
The synthesis of ethyl 6aryl4oxo4,6dihdro11213Hpyrimido2′,1′:4,51,3,5triazino1,2abenzimidazole3carboxylates 4ap was described viapyrimidine ring annulation to 4aryl3,4dihydro1,3,5triazino1,2abenzimidazole2amines 2ap which were obtained from 2guanidinobenzimidazole 1. Tautomerism in the prepared compounds was investigated using nmr spectroscopy. Compounds 2apwere found to be present in dimethyl sulfoxide solution predominantly as 3,4dihyhydro tautomeric form. Compounds 4apexisted in dynamic equilibrium of 1, 12 and 13Hforms. It was found that methylation of 4adled to 13methyl substituted derivatives 9adexclusively. |
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