2-Amino-3-nitroso-4//-pyrido pyrimidin-4-ones, reduction

The 3-amino group of 3,4-diamino-2//-pyrido[l,2-u]pyrimidin-2-ones 216, obtained from 3-nitroso derivatives by reduction with Na2S204 in 30% NH4OH at 70-80 °C, was acylated with acyl chlorides, and the acylated products 217 were cyclized to pyrido[2,l-Z)]purin-10-ones 218 by treatment with NaOMe (95JHC1725). 

Reduction of 3-nitroso derivative 329 by treatment with activated zinc dust in boiling acetic acid for 6 hours gave 3-amino derivative 330 [91IJC(B)839]. 2,3-Diamino-4//-pyrido[ 1,2-a]pyrimidin-4-one was pre-... 

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