Figure 10

General synthetic procedure followed for the preparation of 54, 55. (i) NEt3, THF, r.t. 3 h; (ii) NaOH, EtOH, r.t. 30 min; (iii) pyridine, r.t. o.n.; (iv) K3PO4, Pd(dppf), H2O/DMF, 130 °C 75 min (microwave); (v) AcOH, 120 °C 3 h.
General synthetic procedure followed for the preparation of 54, 55. (i) NEt3, THF, r.t. 3 h; (ii) NaOH, EtOH, r.t. 30 min; (iii) pyridine, r.t. o.n.; (iv) K3PO4, Pd(dppf), H2O/DMF, 130 °C 75 min (microwave); (v) AcOH, 120 °C 3 h.