Reaction #5773

Reaction equation

Thionyl chloride

sodium azide

Triethylamine

2-bromo-N-(4-nitrophenyl)benzamide

DMF

Triethylamine

→

5-(2-bromophenyl)-1-(4-nitrophenyl)-1H-tetrazole

Yield 73.0%

Solvents

acetonitrile

water

Conditions

Workup

1. 1
   Otherthe reaction temperature below 25° C
2. 2
   workup.STIRRINGThe mixture was stirred for 5 hours at ambient temperature
3. 3
   workup.STIRRINGThe mixture was stirred for 2 hours at 10° C.
4. 4
   Temperatureto warm to ambient temperature
5. 5
   workup.STIRRINGstirred for 24 hours
6. 6
   Filtrationthe precipitated solid collected by filtration
7. 7
   OtherThe solid was purified by trituration with a hot mixture of ethyl acetate (26 ml), hexane (2.6 ml) and triethylamine (0.1 ml)

Procedure

Triethylamine (1.04 g; 10.38 mmol) was added to a mixture of 2-bromo-N-(4-nitrophenyl)benzamide (3 g; 9.35 mmol) in acetonitrile (12 ml) and DMF (0.189 g; 2.58 mmol) and the mixture was stirred for 90 minutes. Thionyl chloride (1.44 g; 12.14 mmol) was then added slowly keeping the reaction temperature below 25° C. The mixture was stirred for 5 hours at ambient temperature and then cooled to 10° C. Triethylamine (2.83 g; 28 mmol) was then added, followed by sodium azide (1.33 g; 20.4 mmol) and tetrabutylammonium bromide (0.42 g; 1.3 mmol). The mixture was stirred for 2 hours at 10° C. and then allowed to warm to ambient temperature and stirred for 24 hours. The mixture was poured into excess water and the precipitated solid collected by filtration. The solid was purified by trituration with a hot mixture of ethyl acetate (26 ml), hexane (2.6 ml) and triethylamine (0.1 ml) to give 5-(2-bromophenyl)-1-(4-nitrophenyl)-1H-tetrazole (B) (2.36 g; 73% yield) as an off-white solid; NMR (d6 -acetone; 270 MHz): 7.61-7.86(m, 6H), 8.41(d, 2H); microanalysis, found: C, 44.8; H, 2.1; N, 20.0; Br, 23.6%; C13H8BrN5O2 requires: C, 45.1; H, 2.3; N, 20.2; Br, 23.1%.

Source