Hydrochloric Acid → 8,9-Dimethoxy-1,2,3,11b-tetrahydrochromeno[4,3,2-de]isoquinoline

HRID 895677Notes

Reaction equation

HRID 895677 reaction equation
[CH3:1][O:2][C:3]1[C:8]2[O:9][C:10]3[C:11]4[C:16]([CH:17]=[CH:18][CH:19]=3)=[CH:15][N:14]=[CH:13][C:12]=4[C:7]=2[CH:6]=[CH:5][C:4]=1[O:20][CH3:21].Cl>[Pt](=O)=O.C(O)(=O)C>[CH3:1][O:2][C:3]1[C:8]2[O:9][C:10]3[C:11]4[CH:12]([CH2:13][NH:14][CH2:15][C:16]=4[CH:17]=[CH:18][CH:19]=3)[C:7]=2[CH:6]=[CH:5][C:4]=1[O:20][CH3:21]

Participants

5

Reactant 2

HCID 313Hydrochloric AcidHCID 129719218,9-Dimethoxychromeno[4,3,2-de]isoquinoline

Product 1

HCID 129719228,9-Dimethoxy-1,2,3,11b-tetrahydrochromeno[4,3,2-de]isoquinoline

Reagents, catalysts & solvents 2

HCID 345198Adams' catalystCatalystHCID 176Acetic AcidSolvent

Procedure

Platinum (IV) oxide (200 mg) was added to a solution containing 50 ml of acetic acid and isoquinoline 6 (1 g; 3.5 mmol). After adding 2.8 ml of concentrated HCl, the mixture was shaken on a Parr hydrogenator at 60 psi for 24 hours. The green solution was filtered through Celite to remove the catalyst and the majority of the acetic acid was removed by rotary evaporation. The remaining acid was neutralized using a saturated sodium bicarbonate solution, extracted with diethyl ether (3×250 ml), dried (Na2SO4), and concentrated. The resulting oil (0.997 g; 99%) was used without further purification: 1H NMR: (300 MHz, CDCl3): 7.10 (t, 1H, J=7.5 Hz); 7.00 (d, 1H, J=8.4 Hz); 6.78 (m, 2H); 6.60 (d, 1H, J=9 Hz); 4.10 (s, 2H); 3.84 (m, 8H); 2.93 (t, 1H, J=12.9 Hz).

Workup

  1. filtrationThe green solution was filtered through Celite
  2. customto remove the catalyst
  3. customthe majority of the acetic acid was removed by rotary evaporation
  4. extractionextracted with diethyl ether (3×250 ml)
  5. dry with materialdried (Na2SO4)
  6. concentrationconcentrated
  7. customThe resulting oil (0.997 g; 99%) was used without further purification

Sources & evidence

ORD record
ord-f17a8710fb514272b5895c9d937fa8f5
Source dataset
uspto-grants-2005_07
Patent number
US06916832B2

Reaction notes

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