Synthesis of analogs containing methylated urea functionality and analogs with the amide linker. Reagents and conditions: (a) Boc anhydride, TEA, DCM; (b) NaH, CH3I, DMF; (c) TFA, DCM; (d) 48j, DCM. 0 °C to 32 °C; (e) NaH, CH3I, DMF; (f) NaHCO3, isocyanuric chloride, TEMPO (cat.), NaBr (cat.), water: acetone (1:3.5), 0 °C to 25 °C; (g) i) oxalyl chloride, DMF, ii) 47j, TEA, DCM; (h) oxalyl chloride, DMF (cat.), DCM, rt, 1 hr; (i) 29a, TEA, DCM, rt, 12 hrs.