Phenyl isocyanate → HCID 21946008, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of (±)-[1-(2,4-dichloro-pyrimidin-5-yl)-propyl]-(4-methoxy-phenyl)-amine (0.19 g; 0.59 mmol) (from Example 7c supra) in toluene (2 mL) was added phenyl isocyanate (83 μL; 0.76 mmol) (Aldrich). The solution was heated in an oil bath at 110° C. for 1 hour. Upon cooling to room temperature, the reaction was concentrated. The residue was triturated with hexanes and then dried briefly under high vacuum. The solid residue (intermediate urea) was dissolved in freshly distilled tetrahydrofuran (2 mL), cooled to −3° C. and treated with potassium tert-butoxide (1.0 M in tetrahydrofuran; 0.65 mL; 0.65 mmol) (Aldrich). After 15 minutes in the cold, the reaction mixture was filtered through a silica gel pad (1 g) and washed with ethyl acetate. The filtrate was concentrated and purified by flash chromatography (Biotage, 40S, 20:80 to 40:60 ethyl acetate-hexanes gradient) to give (±)-7-chloro-4-ethyl-3-(4-methoxy-phenyl)-1-phenyl-3,4-dihydro-1H-pyrimido[4,5-d]pyrimidin-2-one as a solid. (Yield 0.14 g; 60.2%). The NMR of this material showed only two singlets for the pyrimidine proton indicating a mixture of the desired product and the corresponding 7-bromo compound.

Provenance & Evidence