Trifluoroacetic acid → Dihydro-1-[3-butyloxyphenyl]-1,2,4-triazine-3,5-(2H,4H)-dione

Participants

Reaction Steps

Trifluoroacetic acid (1.2 ml, 15.5 mmol) was added to a suspension of sodium cyanate (1.17 g, 18.0 mmol) and hydrazine (Intermediate 47 1.30 g, 5.15 mmol) in toluene (17 ml) at room temperature and stirred for 2 h. The reaction was quenched with sodium bicarbonate solution, extracted with ethyl acetate and washed with sodium bicarbonate, water and brine, dried (Na2SO4) and concentrated to afford the urea intermediate as a brown oil. A portion of this crude urea (0.65 g, 2.2 mmol) was taken up in methanol (10 ml) and treated with sodium methoxide (0.48 g, 8.8 mmol) at room temperature for 2 h. The reaction was quenched (pH 6.5 buffer), extracted with ethyl acetate, washed with water followed by brine, dried (Na2SO4) and concentrated to afford a red oil which was triturated with ether to afford a pale brown solid (105 mg, 18%), m.p. 100°-105°.

Provenance & Evidence