Sulfuric Acid → 5-bromo-6-methoxy-3,4-dihydro-2H-naphthalen-1-one

HRID 594788Notes

Reaction equation

HRID 594788 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][CH:12]=1)[C:9](=[O:13])[CH2:8][CH2:7][CH2:6]2.C1C(=O)N([Br:21])C(=O)C1.OS(O)(=O)=O>O>[Br:21][C:4]1[C:3]([O:2][CH3:1])=[CH:12][CH:11]=[C:10]2[C:5]=1[CH2:6][CH2:7][CH2:8][C:9]2=[O:13]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 141126-Methoxy-alpha-tetraloneHCID 67184N-bromobutanimide

Product 1

HCID 43042315-bromo-6-methoxy-3,4-dihydro-2H-naphthalen-1-oneYield 41.3%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
60 °C

Procedure

To a suspension of 6-methoxy-1-tetralone (2.0 g, 11.4 mmol) and NBS (2.0 g, 11.4 mmol) in H2O (30 mL) was added conc. H2SO4 (1.2 mL, 22.7 mmol) at rt. The reaction was stirred at 60° C. for 3 h. The mixture was filtered, and concentrated. Purification by prep-HPLC gave 1.2 g (41%) of the title compound as a white solid. 1H NMR (400 MHz, CDCl3): δ 2.13-2.18 (2H, m), 2.61 (2H, t, J=6.0 Hz), 3.03 (2H, t, J=6.0 Hz), 3.97 (3H, s), 6.88 (1H, d, J=8.8 Hz), 8.06 (1H, d, J=8.8 Hz). [M+H] Calc'd for C11H11BrO2, 255, 257. Found, 255, 257.

Workup

  1. filtrationThe mixture was filtered
  2. concentrationconcentrated
  3. customPurification

Sources & evidence

ORD record
ord-7d98dc3c83e8434ba3386721e52e4360
Source dataset
uspto-grants-2016_01
Patent number
US09242968B2

Reaction notes

Loading…