p-Toluenesulfonic acid monohydrate → (S)-methyl 2-(4-bromo-8-oxo-6,7,8,10-tetrahydro-3H-oxepino[3,4-e]indazol-7-yl)acetate

HRID 2378693Notes

Reaction equation

HRID 2378693 reaction equation
Br[C:2]1[C:10]2[C:5](=[C:6]([Br:24])[CH:7]=[C:8]([CH2:13][C@@H:14]([CH2:19][C:20]([O:22][CH3:23])=[O:21])[C:15]([O:17][CH3:18])=[O:16])[C:9]=2CO)[NH:4][N:3]=1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1.C(OCC)(=O)C>[Br:24][C:6]1[C:5]2[NH:4][N:3]=[CH:2][C:10]=2[C:9]2[CH2:18][O:17][C:15](=[O:16])[C@H:14]([CH2:19][C:20]([O:22][CH3:23])=[O:21])[CH2:13][C:8]=2[CH:7]=1

Participants

5

Reactant 2

HCID 521998p-Toluenesulfonic acid monohydrateHCID 178500724(S)-dimethyl 2-((3,7-dibromo-4-(hydroxymethyl)-1H-indazol-5-yl)methyl)succinate

Product 1

HCID 59732087(S)-methyl 2-(4-bromo-8-oxo-6,7,8,10-tetrahydro-3H-oxepino[3,4-e]indazol-7-yl)acetateYield 42%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8857Ethyl AcetateSolvent

Procedure

(S)-Dimethyl 2-((3,7-dibromo-4-(hydroxymethyl)-1H-indazol-5-yl)methyl)succinate (440 mg, 1.065 mmol) was dissolved in toluene (30 mL). p-Toluenesulfonic acid monohydrate (28 mg, 0.147 mmol) was added to the mixture. Reaction was warmed to reflux and held for 18 hours with stirring. Mixture was cooled to room temperature and then diluted with ethyl acetate. Material was washed with aqueous sodium bicarbonate and the aqueous phase was discarded. Organics were dried MgSO4, filtered and then concentrated to dryness. Silica gel chromatography eluting ethyl acetate-hexanes afforded the title compound as amber oil in 42% yield. MS (M+H)+=367.2, 369.2.

Workup

  1. customReaction
  2. temperaturewas warmed
  3. temperatureto reflux
  4. washMaterial was washed with aqueous sodium bicarbonate
  5. filtrationfiltered
  6. concentrationconcentrated to dryness
  7. washSilica gel chromatography eluting ethyl acetate-hexanes

Sources & evidence

ORD record
ord-5f1c75d205e34ec8b2042abefc60f517
Source dataset
uspto-grants-2008_12
Patent number
US07470679B2

Reaction notes

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