Thionyl Chloride → 1-(Chloromethyl)-1H-benzotriazole

HRID 1756475Notes

Reaction equation

HRID 1756475 reaction equation
O[CH2:2][N:3]1[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]=2[N:5]=[N:4]1.S(Cl)([Cl:14])=O>>[Cl:14][CH2:2][N:3]1[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]=2[N:5]=[N:4]1

Participants

3

Reactant 2

HCID 24386Thionyl ChlorideHCID 2241691H-Benzotriazole-1-methanol

Product 1

HCID 33282221-(Chloromethyl)-1H-benzotriazoleYield 82.9%

Procedure

1-Chloromethyl benzotriazole was prepared using the procedure outlined in JACS 74, 3869 (1952). Solid 1-hydroxymethyl benzotriazole (45.0 parts) was stirred mechanically and thionyl chloride (130 parts) was added dropwise at a fairly rapid rate so that the slurry could be agitated while immersed in an ice bath. A nitrogen sweep was employed so that the gasses evolved could be bubbled through a dilute sodium hydroxide solution. After all of the thionyl chloride had been added, the mixture was allowed to warm to room temperature. The mixture was heated to 40° C. and gas evolution became vigorous and the caked-up solid dissolved to yield a clear, pale yellow solution. The mixture was warmed to 65° C. where it was held for 60 minutes. Excess thionyl chloride was distilled off slowly and when distillation ceased, the mixture was cooled to 35°-40° C. and 100 parts of methanol was added to scavenge any residual thionyl chloride. The solution was warmed to reflux and the precipitated solid was broken up with a stirring rod. After 15 minutes at reflux the solution was cooled in an ice bath for 30 minutes and the pale brown solid was filtered and dried in a vacuum oven. The yield of 1-chloromethyl benzotriazole was 41.6 parts (82.9% yield), m.p. 137°-139° C., literature 136°-8° C.

Workup

  1. customwhile immersed in an ice bath
  2. customevolved could be bubbled through a dilute sodium hydroxide solution
  3. additionAfter all of the thionyl chloride had been added
  4. temperatureThe mixture was heated to 40° C.
  5. dissolutionthe caked-up solid dissolved
  6. customto yield a clear, pale yellow solution
  7. temperatureThe mixture was warmed to 65° C. where it
  8. distillationExcess thionyl chloride was distilled off slowly
  9. distillationwhen distillation
  10. temperaturethe mixture was cooled to 35°-40° C.
  11. addition100 parts of methanol was added
  12. temperatureThe solution was warmed
  13. temperatureto reflux
  14. temperatureAfter 15 minutes at reflux the solution
  15. temperaturewas cooled in an ice bath for 30 minutes
  16. filtrationthe pale brown solid was filtered
  17. customdried in a vacuum oven
  18. custom41.6 parts (82.9% yield), m.p. 137°-139° C., literature 136°-8° C.

Sources & evidence

ORD record
ord-9d87e1fb97124043b8f2e3ed2d94261b
Source dataset
uspto-grants-1995_08
Patent number
US05441563

Reaction notes

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