Triethylamine → 5H-1,4-Benzodioxepin-2,5(3H)-dione

HRID 1090755Notes

Reaction equation

HRID 1090755 reaction equation
C(N(CC)CC)C.Br[CH2:9][C:10]([O:12][C:13]1[C:14](=[CH:18][CH:19]=[CH:20][CH:21]=1)[C:15]([OH:17])=[O:16])=[O:11]>C1(C)C=CC=CC=1>[O:12]1[C:13]2[CH:21]=[CH:20][CH:19]=[CH:18][C:14]=2[C:15](=[O:17])[O:16][CH2:9][C:10]1=[O:11]

Participants

4

Reactant 2

HCID 8471TriethylamineHCID 1317722-[(Bromoacetyl)oxy]benzoic acid

Product 1

HCID 3019635H-1,4-Benzodioxepin-2,5(3H)-dione

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Procedure

The triethylamine solution was added all at once to the refluxing solution of bromoacetylsalicylic acid. The addition took thirty seconds. Moments later, the byproduct Et3NHBr crystallized out of solution. The suspension was refluxed for one hour and then allowed to cool. The salt crystals were isolated by vacuum filtration, washed with 25 mL of acetone, air dried in the Bucher funnel, and finally vacuum dried at room temperature. 2.27 grams of triethylammonium bromide were collected. MP=249°-252° C. with decomposition. The filtrate was evaporated down, and a white solid was obtained which was then dissolved in 25 mL of boiling toluene. Everything did not dissolve. The hot toluene solution was gravity filtered into a 25 mL Erlenmeyer flask. A white solid started to crystallize after a few minutes. The insoluble material was soluble in water which strongly suggested that it was Et3NHBr. After standing overnight at room temperature, the crystals were isolated by suction filtration, washed with 20 mL of toluene, and vacuum dried at room temperature for five hours. 1.17 grams were collected (43% yield). MP-112°-114° C. at 3.5° C./minute. IR (KBr pellet) 1795, 1730, 1605, 1455, 1315, 1190, 1120, 1025, 930, 763 cm-1. 300 MHz 1H NMR (CDCl3): δ4.75 singlet (2H), δ7.30 doublet (1H). One of the lines overlapped with the chloroform signal. δ7.42 triplet (1H), δ7.70 triplet (1H), δ7.95 doublet (1H).

Workup

  1. additionThe addition
  2. waittook thirty seconds
  3. customMoments later, the byproduct Et3NHBr crystallized out of solution
  4. temperatureThe suspension was refluxed for one hour
  5. temperatureto cool
  6. customThe salt crystals were isolated by vacuum filtration
  7. washwashed with 25 mL of acetone, air
  8. customdried in the Bucher funnel, and finally vacuum
  9. customdried at room temperature
  10. custom2.27 grams of triethylammonium bromide were collected
  11. customThe filtrate was evaporated down
  12. customa white solid was obtained which
  13. dissolutionEverything did not dissolve
  14. filtrationfiltered into a 25 mL Erlenmeyer flask
  15. customto crystallize after a few minutes
  16. customthe crystals were isolated by suction filtration
  17. washwashed with 20 mL of toluene, and vacuum
  18. customdried at room temperature for five hours
  19. custom1.17 grams were collected (43% yield)

Sources & evidence

ORD record
ord-a2aa0d57b4bd461ebc8fd4a4a987e182
Source dataset
uspto-grants-1992_01
Patent number
US05082925

Reaction notes

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