Phosphorus oxychloride (0.08 ml) was added to a mixture of 4-methyl-3-[6-(4-methylpiperazin-1-yl)-4-oxoquinazolin-3(4H)-yl]benzoic acid (0.30 g), cyclobutylamine (0.09 ml) and pyridine (5 ml) and the resultant was heated to 120° C. for 5 minutes in a microwave (Personal Chemistry Emrys Optimizer with 300 W magnetron). The mixture was evaporated. The residue was partitioned between ethyl acetate and saturated NaHCO3 solution. The organic phase was dried (magnesium sulphate) and evaporated and the residue purified by column chromatography on a silica column using initially methylene chloride and then a 9:1 mixture of methylene chloride and methanol as eluent. There was thus obtained the title compound (0.16 g); NMR Spectrum: (DMSOd6) 1.68 (m, 2H), 2.05 (m, 2H), 2.14 (s, 3H), 2.20 (m, 2H), 2.24 (s, 3H), 2.48 (m, 4H), 3.29 (m, 4H), 4.42 (m, 1H), 7.49 (d, 1H), 7.53 (d, 1H), 7.65 (m, 2H), 7.87 (d, 1H), 7.92 (m, 1H), 8.10 (s, 1H), 8.60 (d, 1H); Mass Spectrum: M+H+ 432.
