A mixture of 12.80 g of 4-[(3-chloro-4-fluorophenyl)amino]-6-nitro-7-((R)-tetrahydrofuran-3-yloxy)quinazoline, 200 ml of ethanol, 100 ml of water, and 17.20 ml of glacial acetic acid is heated to reflux temperature. Then a total of 7.00 g of iron powder is added in batches. The reaction mixture is refluxed for about four hours and then cooled to ambient temperature overnight. For working up, the reaction mixture is evaporated using the rotary evaporator. The residue is taken up in methylene chloride/methanol (9:1), mixed with 20 ml of concentrated ammonia solution and filtered through a layer of silica gel. It is washed with copious amounts of methylene chloride/methanol (9:1) and the combined filtrates are evaporated down. The residue is stirred with diethylether and suction filtered. Yield: 8.59 g (73% of theory); mass spectrum (ESI−): m/z=373, 375 [M−H]−; Rf value: 0.27 (silica gel, ethyl acetate/methanol=9:1).
