Experimental details described
in the Supporting Information. Scheme conditions:
(a) (i) NaH, DMF; (ii) Chloramine solution in MTBE (90%); (b) (i)
3,3-diethyoxypropionitrile, IPA, 85 °C; (ii) DBU, DCE, 85 °C
(c) POCl3, 75 °C. 29%, 2 steps); (d) Conc. H2SO4, 55 °C (89%); (e) R-NH2; (f) Ar–B(OH)2/Suzuki conditions; (g) EtSH, K2CO3,
DMF, rt, 18 h (65%); (h) ArB(OH)2, X-Phos, Pd(OAc)2, 2 M K3PO4, dioxane 125 °C ; (i)
oxone, acetone, water; (j) R-NH2, DMF, 85 °C.