Condensation of 2-chloronitrobenzene (I) with 2-hydroxy-4-methoxybenzaldehyde (II) by means of Cu/KOH in refluxing DMF provides derivative (III), which is then oxidized with KMnO4 in pyridine/H2O to afford carboxylic acid (IV). Reduction of the nitro moiety of (IV) by hydrogenation over Pd/C yields amine (V), which is then cyclized at high temperatures to furnish the dibenzo[b,f][1,4]oxazepinone intermediate (VI) (1). O-Demethylation of (VI) by treatment with AlCl3 in ethylmercaptan (EtSH) gives hydroxy derivative (VII), which then reacts with triflic anhydride in CH2Cl2 in the presence of Et3N to provide compound (VIII). Treatment of (VIII) with POCl3 in refluxing toluene in the presence of N,N-dimethylaniline yields chloro derivative (IX), which is finally condensed with N-methylpiperazine (X) in refluxing toluene to give the desired product.

Condensation of 2-chloronitrobenzene (I) with 2-hydroxy-4-methoxybenzaldehyde (II) by means of Cu/KOH in refluxing DMF provides derivative (III), which is then oxidized with KMnO4 in pyridine/H2O to afford carboxylic acid (IV). Reduction of the nitro moiety of (IV) by hydrogenation over Pd/C yields amine (V), which is then cyclized at high temperatures to furnish the dibenzo[b,f][1,4]oxazepinone intermediate (VI) (1). O-Demethylation of (VI) by treatment with AlCl3 in ethylmercaptan (EtSH) gives hydroxy derivative (VII), which then reacts with triflic anhydride in CH2Cl2 in the presence of Et3N to provide compound (VIII). Treatment of (VIII) with POCl3 in refluxing toluene in the presence of N,N-dimethylaniline yields chloro derivative (IX), which is finally condensed with N-methylpiperazine (X) in refluxing toluene to give the desired product.