3-(2,4-Dichlorophenoxy)-4-methylsulphonylaminobenzene-sulphonic acid chloride (1.36 g, 3.2 mmol) was dissolved in dioxan (5 ml) and at 0° C. added dropwise to a solution of morpholine (2.25 ml, 25.6 mmol) in 1N aqueous NaOH (26 ml, 26 mmol) and dioxan (20 ml). The mixture was stirred for 1 hour at 0° C., acidified with 1N HCl and extracted with ethyl acetate. The combined organic phases were dried over MgSO4 and the solvent was evaporated off. The residue was purified by chromatography (silica gel, CH2Cl2 /ethyl acetate 9/1). Yield: 0.93 g=60% 13C (100 MHz, DMSO-d6) δ 150.02, 147.15, 133.44, 130.43, 129.51, 129.31, 129.18, 126.23, .125.98, 123.95, 123.02, 122.51, 116.78, 115.83, 65.41, 45.83, 41.03
