Hydrochloric Acid → 4-Bromo-6,7-dihydro-7-methyl-8(5H)-isoquinolinone

HRID 530345Notes

Reaction equation

HRID 530345 reaction equation
CO[C:3]([C:5]1(C)[C:14](=[O:15])[C:13]2[CH:12]=[N:11][CH:10]=[C:9]([Br:16])[C:8]=2[CH2:7][CH2:6]1)=O.Cl>>[Br:16][C:9]1[C:8]2[CH2:7][CH2:6][CH:5]([CH3:3])[C:14](=[O:15])[C:13]=2[CH:12]=[N:11][CH:10]=1

Participants

3

Reactant 2

HCID 313Hydrochloric AcidHCID 89456261Methyl 4-bromo-5,6,7,8-tetrahydro-7-methyl-8-oxo-7-isoquinolinecarboxylate

Product 1

HCID 894562844-Bromo-6,7-dihydro-7-methyl-8(5H)-isoquinolinoneYield 90.1%

Procedure

(rac)-4-Bromo-7-methyl-8-oxo-5,6,7,8-tetrahydro-isoquinoline-7-carboxylic acid methyl ester (3.3 g, 11.0 mmol) was dissolved in aq. 6 N HCl (28.0 mL, 168 mmol) and heated at reflux for 2.5 h. The acidic solution was concentrated in vacuo, re-suspended in water (ca. 25 mL), cooled in an ice-water bath, and basified with 6 N aq. KOH solution. The aqueous solution was then washed with Et2O (2×) and DCM (3×). The combined organic layers were dried over anhy. Na2SO4, filtered and concentrated in vacuo to afford the title compound (2.38 g, 90% yield) as a brown solid. MS: 240.1 & 242.1 (M+H)+.

Workup

  1. temperatureheated
  2. temperatureat reflux for 2.5 h
  3. concentrationThe acidic solution was concentrated in vacuo
  4. temperaturecooled in an ice-water bath
  5. washThe aqueous solution was then washed with Et2O (2×) and DCM (3×)
  6. customThe combined organic layers were dried over anhy
  7. filtrationNa2SO4, filtered
  8. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-97ffbd4e162c43a0b573095adf3969d5
Source dataset
uspto-grants-2016_05
Patent number
US09353081B2

Reaction notes

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