SEARCH Articles Figures Tables 2- Methyl-8-nitro-9-hydroxy-4//pyrido pyrimidin-4-ones 3- -2-hydroxy-4//-pyrido 9- Hydroxy-2-methyl-3- 2- ethyl 6,7,8,9-tetrahydro-4//-pyrido 9-Hydroxy-2-methyl-4//-pyrido Mannich reaction 9-Hydroxy-2-methyl-4//-pyrido alkylation 9-Hydroxy-2-methyl-4//-pyrido chloride 9-Hydroxy-2-methyl-8-nitro-4//-pyrido