Synthesized 2-[N-( tert -Butoxycarbonyl)amino]thiophene (25) and a similar compound (2-[N-( tert -Butoxycarbonyl)amino]-5-bromothiophene) following the same procedure described in the article as method F.
For the synthesis of 25, the reaction was scaled down 100 times, with a 98 % final yield.
For the synthesis of the bromothiophene analogue, the reaction was also done on a small scale, using the same reactant ratios. The product was not able to be isolated by precipitation because the fine particles made were not able to be caught by the filter. Therefore, the product was extracted into ethylacetate, followed by removal of solvent, trituration with hexanes and filtration (46 % yield).