Hydrochloric Acid → HCID 178431739, compound

HRID 234292Notes

Reaction equation

HRID 234292 reaction equation
[N:1]1([CH2:12][CH2:13][C:14](N)=O)[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[C:4](=O)[C:2]1=[O:3].[OH-:17].[K+].Cl.C1C[O:23]CC1>>[OH:17][C:12]1[C:13]([CH3:14])=[C:4]([C:2]([OH:23])=[O:3])[C:6]2[C:11](=[CH:10][CH:9]=[CH:8][CH:7]=2)[N:1]=1

Participants

5

Reactant 4

HCID 313Hydrochloric AcidHCID 8028Tetrahydrofuran2×HCID 14797Potassium HydroxideHCID 43131892HCID 43131892, compound

Product 1

HCID 178431739HCID 178431739, compound

Procedure

A mixture of 5-chloroisatin acetamide (IV, 5.00 g), potassium hydroxide (1N, 56 ml) and THF (18 ml) is heated at reflux for 1 hr, allowing the THF to boil off, and is allowed to cool to 20°-25°. The basic mixture is cooled to 0° and acidified to pH 5.5 (pH paper) with hydrochloric acid (4N). The resulting solids are filtered, washed with water and methylene chloride, dried, and triturated overnight in methylene chloride (200 ml, to remove a small amount of 5-chloroisatin byproduct). These solids are filtered, washed with methylene chloride, and dried to give 6-chloro-2-hydroxyquinoline-4-carboxylic acid (V), mp >300°; IR (mineral oil) 1711, 1645, 1430, 1221,1179, 887 and 881 cm-1 ; NMR (d6 -DMSO) 12.25,8.30, 7.62, 7.38 and 7.00 δ; MS (El, m/e) 223, 178 and 151.

Workup

  1. temperatureis heated
  2. temperatureat reflux for 1 hr
  3. temperatureto cool to 20°-25°
  4. temperatureThe basic mixture is cooled to 0°
  5. filtrationThe resulting solids are filtered
  6. washwashed with water and methylene chloride
  7. customdried
  8. customtriturated overnight in methylene chloride (200 ml
  9. customto remove a small amount of 5-chloroisatin byproduct)
  10. filtrationThese solids are filtered
  11. washwashed with methylene chloride
  12. customdried

Sources & evidence

ORD record
ord-0ae0b92d7fda4257a6444402c92d638f
Source dataset
uspto-grants-1997_01
Patent number
US05594140

Reaction notes

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