Manufacturing Process
To a solution of 4-bromo-2-fluorobenzylamine and triethylamine in chloroform
was added dropwise a solution of 4-chloro-2-nitrobenzoyl chloride in
chloroform at 0°C with stirring and the mixture was stirred at the same
temperature for 1 h. The reaction mixture was washed in turn with diluted
aqueous hydrochloric acid and water, and then dried. Evaporation of the
solvent followed by recrystallization from diethyl ether gave N-(4-bromo-2-
fluorobenzyl)-4-chloro-2-nitrobenzamide.
A mixture of N-(4-bromo-2-fluorobenzyl)-4-chloro-2-nitrobenzamide and iron
(1.45 g) in acetic acid (66 ml) was stirred at 100°C for 30 min. After cooling,
iron was filtered off. The filtrate was evaporated to give a residue, which was
made alkaline with aqueous 1 N sodium hydroxide and extracted with ethyl
acetate. The extract was washed with water and dried. Removal of the solvent
gave 2-amino-N-(4-bromo-2-fluorobenzyl)-4-chlorobenzamide.
2-Amino-N-(4-bromo-2-fluorobenzyl)-4-chlorobenzamide and N,N'-
carbonyldiimidazole were dissolved in dioxane (50 ml). The solution was
evaporated to give a residue, which was stirred at 150°C for 30 min. After
cooling, the precipitates were collected by filtration and washed with ethanol
to give 3-(4-bromo-2-fluorobenzyl)-7-chloro-1,2,3,4-tetrahydro-2,4-
dioxoquinazoline; melting point >280°C.
To a suspension of 3-(4-bromo-2-fluorobenzyl)-7-chloro-1,2,3,4-tetrahydro-
2,4-dioxoquinazoline in N,N-dimethylformamide was added sodium hydride
(60% in mineral oil) with stirring at 0°C and the mixture was stirred for 15
min at the same temperature. To this mixture was added ethyl bromoacetate
and the mixture was stirred for 1 h at room temperature. The reaction
mixture was poured into diluted hydrochloric acid and extracted with ethyl
acetate. The extract was washed with brine, dried and evaporated to give a
residue. Thus obtained product was purified by recrystallization from isopropyl
ether to give 2-[3-(4-bromo-2-fluorobenzyl)-7-chloro-1,2,3,4-tetrahydro-2,4-
dioxoquinazolin-1-yl]acetic acid melting point 223°-224°C.
