Hydrogen Bromide → HCID 66733495, compound

Participants

Reaction Conditions

Reaction Steps

48% aq. HBr (35 ml) was added to a solution of 1-ethyl-6,7-difluoro-8-methoxy-4-oxo-1,4-dihydro-quinoline-3-carboxylic acid ethyl ester (9.34 g; prepared according to EP 241 206) in AcOH (30 ml). The orange solution was stirred at 110° C. for 24 h. It was poured into water (200 ml) and the grey-white precipitate was filtered. The crystals were collected and dried in vacuo to afford 6.37 g (79% yield) of a beige solid. 1H NMR (DMSOd6; δ ppm): 1.43 (3H, t, J=7); 4.85 (2H, q, J=7); 7.76 (1H, dd, J=8 and J=10); 8.91 (1H, s); 12.02 (1H, broad); 14.90 (1H, broad).

Provenance & Evidence