Sodium Hydroxide → 5-(Trifluoromethyl)-1,2,4-triazin-3-amine

To a stirred solution of sodium acetate trihydrate (22.62 g, 166.2 mmol) in water (80 ml) was added 1,1-dibromo-3,3,3-trifluoroacetone (21.57 g, 79.9 mmol). The solution was heated at reflux under nitrogen for 30 min, then allowed to cool to room temperature before adding solid aminoguanidine bicarbonate (10.88 g, 79.9 mmol). The resulting pale yellow solution (pH 5) was stirred at room temperature for 3 h, then 4 N aqueous NaOH solution (40 ml, 160 mmol) was added causing a precipitate to appear. The mixture (pH 10) was stirred under nitrogen for a further 39 h. The solid was collected by filtration, washed with water and dried at 60° C. under vacuum to give 6.96 g of a mixture of two isomers in a 28:72 ratio. This was further purified by flash chromatography (silica gel, 30% EtOAc/isohexane), then recrystallised from ethanol to afford 3.53 g (27%) of the title compound: 1H NMR (400 MHz, DMSO-d6) δ 8.00 (2H, br s), 9.08 (1H, s).

1. temperatureThe solution was heated
2. temperatureat reflux under nitrogen for 30 min
3. filtrationThe solid was collected by filtration
4. washwashed with water
5. customdried at 60° C. under vacuum

ORD record

ord-05f1036f33e3430cb005bf0bdcaaff02

Source dataset

uspto-grants-2007_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07176203B2