2- Amino-4//-pyrido pyrimidin-4-ones Mannich reactions

Reaction of 2-amino-4/f-pyrido[l,2-n]pyrimidin-4-ones 143 with HNMei -HCl and paraformaldehyde in Dowtherm A afforded a mixture of 3-(A,A-dimethylamino)methyl derivatives 144 and bis-compounds 145 (93FES1225). Mannich reaction of 9-hydroxy-2-methyl-4//-pyri-dor],2-nlpyrimidin-4-one (146) yielded 8-aminomethyl derivatives 147 (94KFZ(10)23). 

Reaction of 2-(A/,N-disubstituted amino)-4//-pyrido[l,2-a]pyrimidin-4-ones 371 (R = H) with an excess of paraformaldehyde and dimethylamine hydrochloride in Dowtherm A at 100-105°C for 90 minutes afforded a mixture of the corresponding Mannich base 711 and 3,3 -methylene bis compound 712 in 12-54% yield, respectively (93FES1225). 

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