用N ,N 二甲基甲酰胺缩二甲醇 [(CH3 ) 2 NCH(OCH3 ) 2 ,1]和蝶呤 (2 氨基 4 羟基蝶啶 )衍生物在极性有机溶剂中反应一般得到脒化产物 :N2 (N ,N 二甲基氨基亚甲基 ) -蝶呤衍生物 .但是在 1,4 二氧六环中进行以上反应时发现 ,N ,N 二甲基甲酰胺缩二甲醇 (1)不仅是脒化试剂 ,而且也是蝶呤化合物的甲基化试剂 ,并且也依据蝶呤的N2 位的不同取代基进行选择性的N(3) 或O4 甲基化反应 Reaction of the N, N-dimethylformamide dimethyl acetal [(CH3) 2 NCH (OCH3) 2,1] with pterin (2 amino 4 hydroxypyridine) derivatives in a polar organic solvent generally gives the amidated product : N2 (N, N-Dimethylaminomethylene) -pterin Derivative However, when carrying out the above reaction in 1,4-dioxane, it was found that N, N-dimethylformamide dimethyl acetal (1) Is not only an amidination reagent but also a methylation reagent for a pterin compound and also performs a selective N (3) or O4 methylation reaction depending on the different substituents of pteridine at the N2 position