Ethyl 2, 3, 4, 8-tetrahydro-3-methyl-2, 4-dioxopyrido [2, 3-d] pyrimidine-6-carboxylates (IV) and their bis-compounds (VI) were synthesized by the condensation of 6-alkyl-or 6-aryl-amino-3-methyluracils (II) and appropriate ethyl 3-chloro-2-formylprop-2-enoates (III) in dimethylformamide. Hydrolysis of the esters IV and VI with base resulted in a novel rearrangement of a substituent (R2) at the 7-position onto the 6-substituent to give the corresponding 6-acyl-1, 2, 3, 4, 7, 8-hexahydro-3-methyl-2, 4, 7-trioxopyrido [2, 3-d] pyrimidines (VII) and their bis-compounds (X). The mechanism of the rearrangement is discussed.
乙基2, 3, 4, 8-四
氢-3-
甲基-2, 4-二
氧吡啶[2, 3-d]
嘧啶-6-
羧酸酯(IV)及其双化合物(VI)是通过6-烷基或6-芳基
氨基-3-
甲基尿
嘧啶(II)与适当的乙基3-
氯-
2-甲酰
丙-2-烯酸酯(III)在二
甲基甲
酰胺中缩合合成的。将
酯IV和VI在碱性条件下
水解,会导致取代基(R2)在7位的重新排列,转移到6位的取代基上,生成对应的6-酰基-1, 2, 3, 4, 7, 8-六
氢-3-
甲基-2, 4, 7-三
氧吡啶[2, 3-d]
嘧啶(VII)及其双化合物(X)。对这种重新排列的机制进行了讨论。