Figure 1: Probe SFP-1 synthesis.
From: Selective fluorescent probes for live-cell monitoring of sulphide
(a) MeOH, H2SO4 (2.0 equivalent), 80 °C, 12 h, 87%; (b) CrO3 (3 equiv.), AcOH (30 equiv.), Ac2O (18 equiv.) H2SO4 (4.5 equiv.) 0 °C, 1 h, 57%; (c) H2SO4, MeOH/H2O (1:1), 100 °C, 30 min, then THF, HCl, 80 °C, 2 h, 78%; (d) 1,3-propanediol (6 equiv.), p-TsOH (0.35 equiv.), anhydrous Na2SO4, 80 °C, 24 h, 80%; (e) NaBH4 (10 equiv.), 1, 4-dioxane/H2O (3:2), 65 °C, 12 h, 70%; (f) PCC (1.5 equiv.), celite, CH2Cl2, 25 °C, 1 h, 90%; (g) 3′,5′-difluoroacetophenone (1.1 equiv.), 5 N NaOH (20 equiv.), EtOH, 25 °C, 2 h, 91%; (h) HCl, THF, 25 °C, 5 h, 99%; (i) RuCl2(PPh3)3 (0.7% equiv.), HCOOH (2.8 equiv.), Et3N (1.7 equiv.), THF, 25 °C, 2 h, 83%; (j) phenylhydrazine (1.3 equiv.), HCl (1.3 equiv.), K2CO3 (0,25 equiv.), EtOH, 90 °C, 12 h, 65%; (k) PCC (5 equiv.), celite, CH2Cl2, 25 °C, 2 h, 86%; (l) Pd(OAc)2 (0.1 equiv.), methyl acrylate (1.2 equiv.), Bu4NAc (3 equiv.), K2CO3 (1.5 equiv.), KCl (1.5 equiv.), DMF, 90 °C, 2 h, 56%. DMF, N,N-dimethylformamide; Et3N, triethylamine; NaBH4, sodium borohydrid; PCC, pyridinium chlorochromate; THF, tetrahydrofuran; p-TsOH, p-toluenesulfonic acid.
