5-(tert-Butoxycarbonyl)-4,5,6,7-tetrahydrothieno[3,2-c]pyridine-2-carboxylic acid (968 mg, 3.42 mmol) and N,O-dimethylhydroxylamine hydrochloride (333 mg, 3.42 mmol) were dissolved in MC (50 ml) and the solution was cooled to 0° C. HOAt (46.5 mg, 0.34 mmol), diisopropylethylamine (0.66 ml, 3.76 mmol) and EDCI (720 mg, 3.76 mmol) were added to this mixture and the mixture was stirred at room temperature overnight. The reaction mixture was diluted with methylene chloride (50 ml) and washed with 0.5 M KHSO4 solution (100 ml), NaHCO3 solution and NaCl solution. The combined organic phases were dried with Na2SO4, filtered and concentrated in vacuo. The product obtained in this way (1.13 g) was employed in the next stage without further purification.
