Alkylation of 3-alkyl-6-methyl-5,7-dioxo-4,5,6,7-tetrahydro-1,2,3-triazolo[4,5-d]pyrimidines I with alkyl halides in dimethylformamide in the presence of potassium carbonate, or by analogous alkylation of sodium salts of compounds I afforded the respective 4-alkyl derivatives III but not 5-alkyloxy-3-alkyl-6-methyl-7-oxo-6,7-dihydro-1,2,3-triazolo[4,5-d]pyrimidines IV or isomeric 1,3-dialkyl-6-methyl-5,7-dioxo-4,5,6,7-tetrahydro-1,2,3-triazolo[4,5-d]pyrimidinium halides II.
在二甲基甲酰胺中,将3-烷基-6-甲基-5,7-二氧代-4,5,6,7-四氢-
1,2,3-三唑[4,5-
d]
嘧啶I与烷基卤化物进行烷基化,或通过类似的方法将化合物
I的钠盐烷基化,得到相应的4-烷基衍
生物III,但不得到5-烷氧基-3-烷基-6-甲基-7-氧代-6,7-二氢-
1,2,3-三唑[4,5-
d]
嘧啶IV或异构体1,3-二烷基-6-甲基-5,7-二氧代-4,5,6,7-四氢-
1,2,3-三唑[4,5-
d]
嘧啶盐
II。