N-bromobutanimide → 9-bromomethyl-3-methylbenzo[f]quinazolin-1(2H)-one

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Reaction Steps

To a hot solution of 3,9-dimethylbenzo[f]quinazolin-1(2H)-one (2.0 g, 8.9 mmol) in benzene (1000 ml) under nitrogen was added N-bromosuccinimide (NBS) (2.0 g, 11 mmol). The solution was stirred at reflux for 1 hour and then concentrated in vacuo to give crude 9-bromomethyl-3-methylbenzo[f]quinazolin-1(2H)-one. The solid was suspended with diethyl N-(4-amino-2-fluorobenzoyl)-L-glutamate (T. R. Jones et al., UK Patent GB 2175 903A, 1986)(6.0 g, 18 mmol) in DMF (20 ml) and stirred under nitrogen at 100° C. for 30 minutes. The reaction mixture was allowed to cool. N-methylmorpholine (1.0 ml, 9.1 mmol) (Aldrich) was added, and the solution concentrated under high vacuum. The residue was purified with silica gel chromatography eluting with methylene chloride:THF (5:1). Fractions containing product were concentrated in vacuo to a thick paste, the solid suspended in a small volume of diethyl ether, filtered under nitrogen, and dried under high vacuum to give diethyl N-(4-(((1,2-dihydro-3-methyl-1-oxobenzo[f]-quinazolin-9-yl)methyl)amino)-2-fluorobenzoyl)-L-glutamate as a white solid (2.3 g).

Provenance & Evidence