To a well-stirred suspension of pentane-washed sodium hydride (0.52 g of 60%, 3 mmole) in 3 ml dry DMF was added 4-amino-5-chloro-N-[2-(diethylamino)ethyl]-2-hydroxybenzamide (3.43 g, 12 mmoles) (prepared as in Example 53). To this was added 10 ml of DMF and the mixture was stirred at ambient temperature for 45 minutes then warmed to about 50° C. for 15 minutes whereupon 4-chloro-N,N-diethylbutyramide (1.92 g, 11 mmoles) was added. The mixture was then stirred at 60°-70° C. for 6 hours, at room temperature for 2 days and then at 60-70° C. for a further 4 hours. After cooling, the mixture was poured into 400 ml of brine and extracted with methylene chloride (4×100 ml). After combining, the organic phase was washed two times with 100 ml of 10% aqueous sodium hydroxide and brine, dried over sodium sulfate, filtered and concentrated in vacuo to give an oil (3.75 g). This was purified by flash chromatography on silica gel to give 1.64 g of the title compound as an oil.
