反应详情

A solution of crude title compound of Step C (5.8 g) in toluene (85 mL) was cooled to 0° C. under N2. While stirring the reaction solution, 1,1-dimethylhydrazine (2.5 mL) was added and the mixture was allowed to warm to room temperature. After stirring for 30 min at room temperature, a precipitate formed. Filtration afforded 5.1 g of the title compound of Step D as a white solid melting at 152-153° C. 1H NMR (CDCl3): δ 8.48 (br s,1H), 7.89 (d,1H), 7.77 (m,1H), 7.58 (d,1H), 7.34 (t,1H), 7.17 (m,2H), 5.72 (br s,1H), 3.93 (s,3H), 2.72 (s,6H).

1. additionwas added
2. customa precipitate formed
3. filtrationFiltration