Potassium Bromide → HCID 10584244, compound

HRID 726213Notes

Reaction equation

HRID 726213 reaction equation
[CH3:1][O:2][C:3]1[C:4](=[O:15])[C:5]2[CH2:6][CH:7]=[CH:8][CH:9]([CH3:14])[C:10]=2[C:11](=[O:13])[CH:12]=1.[K+].[Br-]>C(Cl)(Cl)Cl.O=[Mn]=O>[CH3:1][O:2][C:3]1[C:4](=[O:15])[C:5]2[C:10]([C:11](=[O:13])[CH:12]=1)=[C:9]([CH3:14])[CH:8]=[CH:7][CH:6]=2

Participants

5

Reactant 2

HCID 253877Potassium BromideHCID 12692025HCID 12692025, compound

Product 1

HCID 10584244HCID 10584244, compoundYield 1,695.6%

Reagents, catalysts & solvents 2

HCID 14801Manganese dioxideCatalystHCID 6212ChloroformSolvent

Procedure

To a solution of 5,8-dihydro-2-methoxy-5-methylnaphthalene-1,4-dione (100 mg, 490 μmol) in CHCl3 (5 mL), there was added MnO2 (213 mg, 2.45 mmol, Fluka). The stirred suspension was heated at reflux for 45 min (progress of the reaction may best be monitored by 1H NMR since TLC gives ambiguous results). The reaction was allowed to cool to rt and was filtered through a pad of Celite (the pad was washed with CHCl3 (3×3 mL)). Solvent removal yielded a yellow powder (99 mg, 100%, pure by TLC and 1H NMR); mp 138.5°-140° C.; 1H NMR δ (CDCl3) 2.76 (s, 3H), 3.88 (s, 3H), 6.11 (s, 1H), 7.54 (m, 2H), 8.07 (dd, J=1.8, 6.6 Hz, 1H); IR (KBr) 2984 (w), 2949 (w), 2927 (w), 2849 (w), 1677 (s), 1646 (s), 1619 (s), 1231 (s), 1078 (m), 1060 (m), 861 (m), 776 (m). Crystallization from MeOH yielded orange needles (mp 140°-141° C.). A 1.8 g run performed in an analogous manner yielded 1.68 g (94%) of product (>95% pure by 1H NMR with the impurity being unreacted starting material).

Workup

  1. temperatureThe stirred suspension was heated
  2. temperatureat reflux for 45 min (
  3. customprogress of the reaction
  4. customgives ambiguous
  5. customresults)
  6. filtrationwas filtered through a pad of Celite (the pad
  7. washwas washed with CHCl3 (3×3 mL))
  8. customSolvent removal
  9. customyielded a yellow powder (99 mg, 100%, pure by TLC and 1H NMR)
  10. customCrystallization from MeOH yielded orange needles (mp 140°-141° C.)

Sources & evidence

ORD record
ord-237cedd37e64481d87d7c5bfa75960ce
Source dataset
uspto-grants-1998_01
Patent number
US05708168

Reaction notes

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