Scheme 1. Synthesis of Riluzole–Rasagiline Hybrids 3–8.
Reagents and conditions: (a) NH4SCN, Br2, AcOH, r.t. (55–85%); (b) NaBH4, BF3·Et2O, dry THF, 70 °C (42%); (c) propargyl bromide, K2CO3, ACN, r.t. (25%); (d) DIBAL-H, DCM, r.t. (76%) (e) propargylamine, NaBH3CN, MeOH, r.t. (60%); (f) formaldehyde (37% in MeOH), NaBH3CN, ACN, r.t. (49%); (g) propargyl bromide, NaH, DMF, r.t. (60%); (h) I2, thiourea, MeOH, MW at 100 °C, 10 min (66%); (i) HBr, 110 °C (96%); (l) propargyl bromide, K2CO3, THF, r.t. (8%), (m) propargyl bromide, NaH, DMF, 0 °C (12%).