Dimethylformamide → 1-(6,7-dimethoxy-4-oxo-3,4-dihydro-quinazolin-2-yl)-1H-pyrazole-4-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

Chlorotrimethylsilane (1.26 mL, 10.0 mmol) was added to a solution of 1-[(3,4-dimethoxy-phenylamino)-ethoxycarbonylimino-methyl]-1H-pyrazole-4-carboxylic acid ethyl ester (0.39 g, 1.0 mmol) and DMF (3 mL), and the resulting mixture was heated to 80° C. for 16 h in a sealed tube. The reaction mixture was cooled and water (2 mL) was added. The crude reaction mixture was concentrated under reduced pressure and the resulting aqueous mixture was adjusted to pH 7 using 2M aqueous NH4OH. The residue was triturated well and collected by vacuum filtration. The titled compound was purified by preparative reverse-phase HPLC (0.28 g, 81%). MS (ESI): mass calcd. for C16H16N4O5, 344.4; m/z found, 345.7 [M+H]+. 1H NMR (400 MHz, DMSO-d6): 13.06-12.23 (br m, 1H), 8.97 (s, 1H), 8.28 (s, 1H), 7.47 (s, 1H), 7.21 (s, 1H), 4.29 (q, J=7.1 Hz, 2H), 3.93 (s, 3H), 3.89 (s, 3H), 1.32 (t, J=7.1 Hz, 3H).

Provenance & Evidence