2-Bromopropanedial → 6-Bromo-2-tert-butyl-[1,2,4]triazolo[1,5-a]pyrimidine

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Reaction Conditions

Reaction Steps

3-tert-Butyl-1H-1,2,4-triazol-5-amine (CAS 202403-45-0) (35%, 13 g, 32.5 mmol) was dissolved in acetic acid (50 ml) and 2-bromomalonaldehyde (7.35 g, 48.7 mmol, 1.5 equiv.) was added. The reaction mixture was stirred for 3 hours at 60° C. The reaction mixture was evaporated and neutralized with saturated NaHCO3 solution 2N and extracted two times with dichloromethane. The organic extracts were dried with sodium sulfate, filtered and evaporated to dryness. The crude product was purified by flash chromatography on 70 g silica gel (heptane:EtOAc 100:0→50:50). The desired 6-bromo-2-tert-butyl-[1,2,4]triazolo[1,5-a]pyrimidine (6.83 g, 83% yield) was obtained as a white solid, MS: m/e=255.0/257.1 (M+H+).

Provenance & Evidence