Sulfuric Acid → HCID 1115345, compound

HRID 2207056Notes

Reaction equation

HRID 2207056 reaction equation
OS(O)(=O)=O.[NH2:6][C:7]1[C:20]2[C:19](=[O:21])[C:18]3[C:13](=[CH:14][CH:15]=[CH:16][CH:17]=3)[C:12](=[O:22])[C:11]=2[C:10]([Br:23])=[CH:9][C:8]=1[Br:24].S([O-])(O)(=O)=O.C1([N+]#N)C2C(=O)C3C(=CC=CC=3)C(=O)C=2C=CC=1.[N-]=[N+]=[N-].[Na+]>O>[Br:24][C:8]1[C:7]2=[N:6][O:21][C:19]3=[C:20]2[C:11]([C:12](=[O:22])[C:13]2[C:18]3=[CH:17][CH:16]=[CH:15][CH:14]=2)=[C:10]([Br:23])[CH:9]=1

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 66811-Amino-2,4-dibromoanthraquinoneHCID 33557Sodium AzideHCID 665091-Anthracenediazonium, 9,10-dihydro-9,10-dioxo-, sulfate (1:1)

Product 1

HCID 1115345HCID 1115345, compoundYield 76.1%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
70 °C

Procedure

3,5-dibromo-6H-anthra[1,9-cd]isoxazol-6-one (1)—Sodium nitrite (993 mg, 14.4 mmol) was added with stirring to conc. H2SO4 (25 mL) at 30-40° C. over 10 min then stirred for an additional 30 min. Next 1-amino-2,4-dibromoanthraquinone (5.0 g, 13.1 mmol) was added over 15 min and the mixture was stirred overnight (16 h) at 50-55° C. The heated solution was poured directly over ice and the resulting yellow precipitate was filtered, washed with cold water, and a 1:1 mixture of ethanol-ether. The moist anthraquinonediazonium hydrogensulfate was added to a solution of NaN3 (1.37 g, 21.0 mmol) in water (25 mL) and stirred overnight (16 h). The light orange solid was filtered off and washed with water followed by a 9:1 mixture of acetone-water. The moist azide was suspended in toluene (40 mL) and heated to 70° C. with stirring. Water and acetone were slowly distilled (using a Dean-Stark apparatus) over a 12 h period. The yellow-orange crystals were filtered and washed with methanol to give 3.78 g (76%) of 3,5-dibromo-6H-anthra[1,9-cd]isoxazol-6-one. 1H NMR (500 MHz, CDCl3) δ 8.44 (d, J=7.8 Hz, 1H), 8.07 (d, J=7.4 Hz, 1H), 7.97 (s, 1H), 7.80 (t, J=7.0 Hz, 1H), 7.71 (t, J=7.4 Hz, 1H). Reference: Sutter, P; Weis, C. D. J. Heterocyclic Chem. 1982, 19, 997-1011.

Workup

  1. stirringthe mixture was stirred overnight (16 h) at 50-55° C
  2. additionThe heated solution was poured directly over ice
  3. filtrationthe resulting yellow precipitate was filtered
  4. washwashed with cold water
  5. additiona 1:1 mixture of ethanol-ether
  6. stirringstirred overnight (16 h)
  7. filtrationThe light orange solid was filtered off
  8. washwashed with water
  9. additionfollowed by a 9:1 mixture of acetone-water
  10. stirringwith stirring
  11. distillationWater and acetone were slowly distilled (
  12. customover a 12 h
  13. filtrationThe yellow-orange crystals were filtered
  14. washwashed with methanol

Sources & evidence

ORD record
ord-82ffb982e48d4d55bce70f07e2135b7c
Source dataset
uspto-grants-2016_06
Patent number
US09376406B2

Reaction notes

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