A suspension of 3-methoxy-4-nitro-N-(4-methanesulfonylamino-3-methoxyphenyl)benzamide (2.03 g) in methanol (50 ml) and ethyl acetate (50 ml) was stirred under hydrogen with palladium on carbon (10%, 50 mg) for 18 hours. The solvents were removed in vacuo to give a brown gum. The residue was dissolved in pyridine (5 ml) and cooled to 0° C. when methanesulfonyl chloride (1 ml) was added, the mixture was kept at 0° C. for a further 2 hours then brought to R.T. for 1 h. The mixture was poured onto ice (50 g) and hydrochloric acid (3M, 50 g), the resultant brown solid filtered and washed with water to give 4-methanesulfonylamino-3-methoxy-N-(4-methanesulfonylamino-3-methoxyphenyl)benzamide (2.1 g, 100%) as a pale brown solid.
