Hydrochloric Acid → Urea, N-[2-[6,7-dihydro-9,10-dimethoxy-4-oxo-2-[(2,4,6-trimethylphenyl)imino]-2H-pyrimido[6,1-a]isoquinolin-3(4H)-yl]ethyl]-

Participants

Reaction Conditions

Reaction Steps

Sodium cyanate (6.0 g, 0.092 mol) in water (100 ml) was added dropwise to a stirred solution of 9,10-Dimethoxy-2-(2,4,6-trimethylphenylimino)-3-(2-aminoethyl)-3,4,6,7-tetrahydro-2H-pyrimido[6,1-a]isoquinolin-4-one, prepared according to Preparation 4 above (20.0 g, 0.046 mol) in water (600 ml) and 1N HCl (92 ml) at 80° C. After stirring for 2 h at 80° C. the mixture was cooled in an ice-bath and basified with 2N NaOH. The mixture was extracted with dichloromethane (3×200 ml) and the combined extract was dried (MgSO4) and evaporated in vacuo. The resulting yellow foam was purified by column chromatography on silica gel eluting with CH2Cl/MeOH (97:3) and triturated with ether to obtain the title compound as a yellow solid, 11.9 g, 54%.

Provenance & Evidence