反应详情

Because 36 could be prepared very cleanly without any of the bis-acylated product using PS-CCD or PyBOP, ester 36 was converted to N-methyl amide 38 (Scheme 6). Ester 36 was cleanly obtained on a preparative scale from 35 using PS-CCD and HOBt in the absence of base. After purification of 36 only by filtration and aqueous extraction, heating at 90° C. in toluene under anhydrous conditions provided the desired amide product 38 in 93% yield over the two steps.

1. customBecause 36 could be prepared very cleanly without any of the bis-acylated product