9-Hydroxy-2-methyl-477-pyrido Mannich reaction

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 l-(3,4-dimethoxybenzyl)-9-hydroxy-l,2,3,4-tetrahydro-8//-pyrido[l,2-a]pyrazin-8-one with 37% formaldehyde solution gave a tetracyclic tetrahydroprotoberberine analogue in a Mannich-type reaction (78AJC187). Reactions of 2,3,4,4a,5,6-hexahydro-l//-pyrazino[l,2-a]-quinolines with 1 W-pyrrolo[2,3-h]pyridine in the presence of 37% aqueous CH20 and AcONa in AcOH, and with 3-dimethylaminomethyl-l //-pyrrolo[2,3-h]pyridine afforded 3-[(l//-pyrrolo[2,3-h]pyridin-3-yl)methyl] derivatives (94MIP6 96USP5576319). 

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