Dimethylformamide → 2,1,3-Benzoxadiazole-5-carbonyl chloride

HRID 238534Notes

Reaction equation

HRID 238534 reaction equation
[N:1]1[O:2][N:3]=[C:4]2[CH:9]=[C:8]([C:10]([OH:12])=O)[CH:7]=[CH:6][C:5]=12.S(Cl)([Cl:15])=O.CN(C=O)C>C1(C)C=CC=CC=1>[N:1]1[O:2][N:3]=[C:4]2[CH:9]=[C:8]([C:10]([Cl:15])=[O:12])[CH:7]=[CH:6][C:5]=12

Participants

5

Reactant 3

HCID 6228DimethylformamideHCID 24386Thionyl ChlorideHCID 27354542,1,3-Benzoxadiazole-5-carboxylic acid

Product 1

HCID 27354532,1,3-Benzoxadiazole-5-carbonyl chlorideYield 79.8%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

In a 500 ml reactor fitted with mechanical stirring, thermometer, addition funnel, reflux condenser and nitrogen inlet, [2,1,3]-benzoxadiazole-5-carboxylic acid (28 g) was suspended in toluene (245 ml). To this suspension was added thionyl chloride (39.4 g) and DMF (0.35 ml). The resulting mixture was heated to reflux and maintained for 3 hours. A short pass column was installed and toluene was distilled (atmospheric pressure, 124 ml) off to remove excess reagent. After cooling the remaining toluene was distilled off, which resulted in a thick oil. This oil was distilled (90° C., 2 mm Hg) to remove impurities and the product crystallized on standing (79.8% yield), mp: 55-58° C.

Workup

  1. customIn a 500 ml reactor fitted with mechanical stirring
  2. additionthermometer, addition funnel
  3. temperaturereflux condenser and nitrogen inlet
  4. temperatureThe resulting mixture was heated
  5. temperatureto reflux
  6. temperaturemaintained for 3 hours
  7. distillationtoluene was distilled (atmospheric pressure, 124 ml) off
  8. customto remove excess reagent
  9. temperatureAfter cooling the remaining toluene
  10. distillationwas distilled off
  11. customwhich resulted in a thick oil
  12. distillationThis oil was distilled (90° C., 2 mm Hg)
  13. customto remove impurities
  14. customthe product crystallized

Sources & evidence

ORD record
ord-ea41652043a44941983bac7cd24c1e90
Source dataset
uspto-grants-2014_02
Patent number
US08642633B2

Reaction notes

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