N,N,N',N',N'',N''-Hexamethylmethanetriamine → 5,6-Dihydropyrido[2,3-h]quinazolin-2-amine

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Reaction Steps

To a refluxing solution, under nitrogen, of 45.0 g (0.306 mol) of 7,8-dihydro-5(6H)-quinolinone, (Example 1), in 750 ml of toluene is added dropwise a solution of 49.8 g (0.343 mol) of tris(dimethylamino)-methane in 250 ml of toluene. The solution is refluxed for 2 hours, cooled and concentrated. The residue is dissolved in 1 l of methanol and treated with 66.2 g (0.367 mol) of guanidine carbonate. The reaction mixture is refluxed, under nitrogen, for 2 hours. The mixture is concentrated to a green solid, the solid is washed with 500 ml of water, filtered and vacuum dried to give 69.1 g of crude product. Recrystallization from acetonitrile affords 6.8 g (77%) of the title compound as a light brown solid; mp 220°-226° C.

Provenance & Evidence