Cesium carbonate → (E)-1-(5-(2-(5,8-dimethyl-[1,2,4]triazolo[1,5-a]pyrazin-2-yl)vinyl)-1-methyl-1H-1,2,4-triazol-3-yl)pyrrolidin-2-one

Participants

Reaction Conditions

Reaction Steps

An argon-purged mixture of (E)-2-(2-(3-bromo-1-methyl-1H-1,2,4-triazol-5-yl)vinyl)-5,8-dimethyl-[1,2,4]triazolo[1,5-a]pyrazine (case 30922, Expl. 9a) p 31) (56 mg, 168 μmol, Eq: 1.00), pyrrolidin-2-one (28.6 mg, 25.7 μl, 336 μmol, Eq: 2), cesium carbonate (76.4 mg, 235 μmol, Eq: 1.4), tris(dibenzylideneacetone)-dipalladium(0)/Pd2(dba)3 (3.07 mg, 3.35 μmol, Eq: 0.02) and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (xant-phos) (3.88 mg, 6.7 μmol, Eq: 0.04) in dioxane (3 ml) was heated in a closed vessel for 1.5 hours at 140° C. under argon atmosphere. Up to 4 additional portions of Pd2(dba)3 and 4,5-bis(diphenylphosphino)-9,9-dimethylxanthene (xant-phos) are added and heating continued for another 1.5 hours until HPLC shows complete conversion of the Aryl bromide. The crude material was applied on silica gel and purified by flash chromatography over a 20 g silica gel column using ethyl acetate/methanol 5-10% as eluent affording 1-{5-[(E)-2-(5,8-dimethyl-[1,2,4]triazolo[1,5-a]pyrazin-2-yl)-vinyl]-1-methyl-1H-[1,2,4]triazol-3-yl}-pyrrolidin-2-one (27 mg, 47.6%) as an off-white solid. MS: m/z=339.6 (M+H+), MP: 242.5° C.

Provenance & Evidence