Several analogs required alternate methods to prepare (Scheme 2). Compound 7 was a product of an unintended side reaction with 2-acetoxybenzoic acid, which yielded only the acetyl substituted arylamine rather than the intended benzamide coupling product. Compound 8 was prepared via traditional HATU amide coupling as the acyl fluoride procedure did not yield the intended product. Finally, analogs 34 and 35 were found to be incompatible with either acyl fluoride coupling procedure and no desired product was obtained. In the case of 35, according to the literature carboxylic acids with α-protons were found to be incompatible with the acyl fluoride method due to competing ketene generation (despite successful synthesis of later analog 36). In the case of 34, the electron-donating character of the 4-dimethylamino substituent on the carboxylic was likely a contributing factor to the inability to isolate product. This led us to scout several amide coupling methods and ultimately the use of a mixed anhydride coupling method using propylphosphonic anhydride (T3P) was employed to obtain 34 and 35.