Formic Acid → 3-(4-bromo-2-fluorobenzyl)-7-chloro-2,4(1H,3H)-quinazolinedione

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Reaction Conditions

Reaction Steps

A solution of 4-bromo-2-fluorobenzyl isocyanate (46.0 g, 0.20 mol) in xylene (100 ml) is metered, at room temperature, into a solution of methyl 4-chloroanthranilate (37.1 g, 0.20 mol) in xylene (250 ml). After the addition has ended, the batch is stirred at 110° C. for 2 hours. 3.60 ml of a 30% solution of methanolic sodium methylate (0.020 mol) are metered in and the mixture is stirred at 90° C. for 2 hours, during which process methanol is distilled off. 1.8 ml of 85% formic acid (0.040 mol) are subsequently added, and the mixture is stirred at 90° C. for a further hour. After cooling, the product is filtered off with suction, washed with 3×50 ml of xylene, 3×50 ml of ethanol and 3×100 ml of water, and dried. 66.1 g of 3-(4-bromo-2-fluorobenzyl)-7-chloro-2,4(1H,3H)-quinazolinedione (yield: 86.2% of theory) of melting point 288 ° to 289° C. (lit. >280° C.) are obtained.

Provenance & Evidence