Hydrochloric Acid → HCID 23050231, compound

HRID 978737Notes

Reaction equation

HRID 978737 reaction equation
C([O:3][C:4]([C:6]1[S:10][C:9]2[CH:11]=[C:12]([O:18][CH3:19])[C:13]([O:16][CH3:17])=[C:14]([Cl:15])[C:8]=2[CH:7]=1)=[O:5])C.O.C(=O)([O-])[O-].[K+].[K+].Cl>CO>[Cl:15][C:14]1[C:8]2[CH:7]=[C:6]([C:4]([OH:5])=[O:3])[S:10][C:9]=2[CH:11]=[C:12]([O:18][CH3:19])[C:13]=1[O:16][CH3:17]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 962Water2×HCID 11430Potassium CarbonateHCID 54344811HCID 54344811, compound

Product 1

HCID 23050231HCID 23050231, compoundYield 100.2%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

4-Chloro-5,6-dimethoxy-benzo[b]thiophene-2-carboxylic acid ethyl ester (29.5 g) was suspended in a mixture of methanol (450 ml), water (75 ml) and potassium carbonate (20.4 g) under an atmosphere of nitrogen. The reaction mixture was heated at reflux for 1 hour then cooled and poured into water (2.5 liter) containing hydrochloric acid (5M, 60 ml). The resultant white solid was filtered and dried at 65° C. under vacuum to give 4-chloro-5,6-dimethoxy-benzo[b]thiophene-2-carboxylic acid (26.8 g). A portion crystallised from dichloromethane:methanol had, m.p. 267°-270° C.

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureat reflux for 1 hour
  3. temperaturethen cooled
  4. filtrationThe resultant white solid was filtered
  5. customdried at 65° C. under vacuum

Sources & evidence

ORD record
ord-16423ba71f6246b4bf946c178d1d586d
Source dataset
uspto-grants-1987_05
Patent number
US04665206

Reaction notes

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