The synthesis of 2-AMINO-4,5,6,7-TETRAHYDRO-1-BENZOTHIOPHENE-3-CARBOXAMIDE is as follows:
A solution of aminothiophene EO (prepared as described in Example C; 500mg, 2.8 mmol) in concentrated sulphuric acid (5ml) was stirred at room temperature for 65 hours. The reaction mixture was poured cautiously into ice-cold aqueous potassium carbonate, diluted with water and extracted with ethyl acetate. The combined organic extracts were washed with water and brine, dried over magnesium sulphate and evaporated to dryness under reduced pressure to give the desired product (383mg, 70%) as an off-white solid.