“…Instead of this Et 2 NH, Et 3 N and pyridine were ineffective in the given protocol and trace or no product was detected (Table 1, entries 11-13). We had additionally tested the impact of various solvents including DMF, DME, THF, ACN, 1,2 DCE, NMP, Toluene, EtOH and EtOH:H 2 O (Table 1, entries [14][15][16][17][18][19][20][21][22]. Solvents such as DMF and DME gave less yield of the product 4aa (Table 1, entries 14 and 15).…”