Lithium Hydroxide → 1-Hydroxyisoquinoline-6-carboxylic acid

HRID 1892574Notes

Reaction equation

HRID 1892574 reaction equation
[O:1]=[C:2]1[C:11]2[C:6](=[CH:7][C:8]([C:12]([O:14]C)=[O:13])=[CH:9][CH:10]=2)[CH:5]=[CH:4][NH:3]1.O1CCCC1.[OH-].[Li+]>O>[O:1]=[C:2]1[C:11]2[C:6](=[CH:7][C:8]([C:12]([OH:14])=[O:13])=[CH:9][CH:10]=2)[CH:5]=[CH:4][NH:3]1

Participants

5

Reactant 3

HCID 3939Lithium HydroxideHCID 8028TetrahydrofuranHCID 42609191Methyl 1-oxo-1,2-dihydroisoquinoline-6-carboxylate

Product 1

HCID 582525541-Hydroxyisoquinoline-6-carboxylic acidYield 48%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

To a mixture of methyl 1-oxo-1.2 dihydroisoquinoline-6-carboxylate (25 g, 0.133 mol), tetrahydrofuran (200 mL) and water (200 mL) was added lithium hydroxide (16.8 g, 0.40 mol) at room temperature, and the mixture was stirred for four hours. Thin layer chromatography (petroleum ether/ethyl acetate 1:1) indicated the reaction was complete. The reaction mixture was extracted with ethyl acetate (100 mL×3) to remove impurities. The aqueous layer was acidified with 4 N aqueous HCl to pH 5 and filtered. The solid was dried in vacuum to give 1-oxo-1.2 dihydroisoquinoline-6-carboxylic acid (11.3 g, 48%) as a light yellow solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 11.48 (s, 1H), 824 (d, 2H), 7.93 (d, 1H), 7.22 (d, 1H), 6.88 (d, 1H).

Workup

  1. extractionThe reaction mixture was extracted with ethyl acetate (100 mL×3)
  2. customto remove impurities
  3. filtrationfiltered
  4. customThe solid was dried in vacuum

Sources & evidence

ORD record
ord-153921e76be24673ad79c2b7fc404308
Source dataset
uspto-grants-2013_08
Patent number
US08507681B2

Reaction notes

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