Sodium hydride → 2-Chloro-6-[4-(3-[2-(2,2,2-trifluoroethyl)guanidino]pyrazol-1-yl)butoxy]pyrazine

Participants

Reaction Steps

Sodium hydride (46 mg. of a 61% w/w dispersion in oil) was added to a hot solution of 1-(4-hydroxybutyl)-3-[2-(2,2,2-trifluoroethyl)guanidino]pyrazole (279 mg.) in dry t-butanol (10 ml.). 2,6-Dichloropyrazine (180 mg.) was added and the mixture was stirred at room temperature for two hours, followed by evaporation in vacuo to dryness. The residue was treated with dilute aqueous 0.5N HCl (10 ml.), and then extracted with EtOAc (4×10 ml.). The combined extracts were dried (MgSO4) and evaporated. The residue was purified by preparative t.l.c. on silica gel plates using triethylamine/EtOH/EtOAc 1:1:9 v/v/v as developing solvent to give 2-chloro-6-[4-(3-[2-(2,2,2-trifluoroethyl)guanidino]pyrazol-1-yl)butoxy]pyrazine (170 mg.; 43%) having the following n.m.r. in d6DMSO: 8.25 (s, 2H); 7.4 (d, 1H); 5.6 (d, 1H); 4.25 (t, 2H); 3.9 (m, 4H); 1.7 (br m, 4H).

Provenance & Evidence