Thioglycolic Acid → 4-Chlorobenzo(b)thiophene-2-carboxylic Acid

HRID 1739455Notes

Reaction equation

HRID 1739455 reaction equation
Cl[C:2]1[CH:9]=[CH:8][CH:7]=[C:6]([Cl:10])[C:3]=1[CH:4]=O.[SH:11][CH2:12][C:13]([OH:15])=[O:14]>CCCC[N+](CCCC)(CCCC)CCCC.[Br-].[OH-].[K+].O>[Cl:10][C:6]1[C:3]2[CH:4]=[C:12]([C:13]([OH:15])=[O:14])[S:11][C:2]=2[CH:9]=[CH:8][CH:7]=1

Participants

6

Reactant 2

HCID 1133Thioglycolic AcidHCID 67372,6-Dichlorobenzaldehyde

Product 1

HCID 38545164-Chlorobenzo(b)thiophene-2-carboxylic AcidYield 85.2%

Reagents, catalysts & solvents 3

HCID 74236Tetrabutylammonium BromideCatalystHCID 962WaterSolvent2×HCID 14797Potassium HydroxideSolvent

Conditions

Temperature
255 fahrenheit

Procedure

In a glass pressure bottle, 2,6-dichlorobenzaldehyde (13.5 g, 0.075 mol) and TBAB (0.4 g) was added to a solution of 2-mercaptoacetic acid (7 ml) in potassium hydroxide (12.5 g) and water (100 ml). The bottle was then sealed and heated in a hot oil bath at 255° F. and 20 psi for 1 hour The bottle was then removed from the hot oil bath and cooled. A pale yellow precipitate was obtained in the bottle. At ambient temperature, the bottle was opened and sufficient water was added to dissolve the precipitate. The resultant aqueous material was washed with ether and then acidified with hydrochloric acid to produce a pale yellow solid. The pale yellow solid was collected on a filter, washed with water and dried, to produce 18.1 g of 4-chloro-2-benzo[b]thiophenecarboxylic acid (85.2% yield, mp 227-231° C.).

Workup

  1. customThe bottle was then sealed
  2. custom20 psi for 1 hour The bottle was then removed from the hot oil bath
  3. temperaturecooled
  4. customA pale yellow precipitate was obtained in the bottle
  5. customAt ambient temperature
  6. dissolutionto dissolve the precipitate
  7. washThe resultant aqueous material was washed with ether
  8. customto produce a pale yellow solid
  9. customThe pale yellow solid was collected on a filter
  10. washwashed with water
  11. customdried

Sources & evidence

ORD record
ord-09cdefe933cf4cbbb652e7e06999949c
Source dataset
uspto-grants-1999_10
Patent number
US05965749

Reaction notes

Loading…