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-f2147dba36774a0aa39f6c040f9baf9b

Source dataset

uspto-grants-2005_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06936608B2