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

Participants

Reaction Conditions

Reaction Steps

Titanium (IV) chloride (2.47 mL, 22.5 mmol) was carefully added to a solution of 1-[(4-bromo-phenylimino)-ethoxycarbonylamino-methyl]-1H-pyrazole-4-carboxylic acid ethyl ester (1.84 g, 4.50 mmol) and DCE (45 mL), and the resulting solution was heated to 100° C. for 15 h. The reaction mixture was cooled to room temperature and poured into ice water (50 mL) and DCM (100 mL) was added. The biphasic mixture was stirred for 2 h, and the layers were separated. The aqueous layer was further extracted with DCM (2×50 mL). The combined organic layers were washed with brine (50 mL), dried (MgSO4), and concentrated. The residue was triturated from EtOH to yield the titled compound (1.05 g, 64% yield). MS (ESI/Cl): mass calcd. for C14H11BrN4O3, 362.0; m/z found, 363.0 [M+H]+. 1H NMR (600 MHz, DMSO-d6): 13.15 (s, 1H), 9.01 (d, J=0.5 Hz, 1H), 8.33 (s, 1H), 8.20 (d, J=2.3 Hz, 1H), 7.99 (dd, J=8.7, 2.4 Hz, 1H), 7.66 (d, J=8.8 Hz, 1H), 4.30 (q, J=7.1 Hz, 2H), 1.32 (t, J=7.1 Hz, 3H).

Provenance & Evidence