A solution of the product from step b) (3.89 g), 7-(2-aminoethyl)4-hydroxy-1,3-benzothiazol-2(3H)-one hydrochloride (3.22 g), bromotripyrrolidinophosphonium hexafluorophosphate, PyBroP, (6.32 g) in dimethylformamide (50 ml) was cooled to -15° C. and diisopropylethylamine (9.0 ml) was added dropwise over 5 minutes. The solution was stirred at -15° C. for 5 min then allowed to warm to 13° C. over 4 hours. This mixture was then added dropwise over 40 min to dilute hydrochloric acid (2N, 500 ml) and after stirring over the weekend the solid was collected by filtration. This solid was dried in vacuo to give the subtitle compound (4.5 g).
