Scheme 2.

Synthesis of Nitrosamides (A) Methyl Acrylate, NaCN, DMF, 40 °C, 4h; (B) NaOH, H₂O, RT, 3h; (C) EDAC, NHS, MeNH₂•HCl, DMSO, RT, 22h; (D) NaNO₂, Ac₂O:HOAc, 0 °C, 4h; (E) HS(CH₂)₃SH, BF₃•OEt₂, THF, 80 °C, 24h; (F) (i) n-BuLi, TMEDA, THF, −78 °C, 1h; (ii) 27, THF, −78 °C to RT, 16h; (G) 25% TFA, CH₂Cl₂, RT, 3h; (H) HCO₂Me, Et₃N, MeOH, 55 °C, 4h; (I) AgNO₃, NCS, MeCN:H₂O (1:1), 0 °C, 30 min; (J) Boc₂O, Et₃N, CH₂Cl₂, RT, 30 min; (K) I₂, PPh₃, Im., CH₂Cl₂, 0 °C-RT, 22h.