Hydrochloric Acid → 1-Benzothiophene-3-carbaldehyde

HRID 542770Notes

Reaction equation

HRID 542770 reaction equation
C([Li])CCC.Br[C:7]1[C:8]2[CH:15]=[CH:14][CH:13]=[CH:12][C:9]=2[S:10][CH:11]=1.CN(C)[CH:18]=[O:19].Cl>CCCCCC.C(OCC)C>[S:10]1[CH:11]=[C:7]([CH:18]=[O:19])[C:8]2[CH:15]=[CH:14][CH:13]=[CH:12][C:9]1=2

Participants

7

Conditions

Temperature
-5 °C

Procedure

To a solution of 17 ml of a 1.6M solution of n-butyl lithium in hexane and 100 ml of dry diethyl ether at -70° C. was added a solution of 5.3 g of 3-bromobenzo[b]thiophene in 65 ml of diethyl ether. After stirring for about 30 minutes, 2.2 ml of dry dimethylformamide in 2.5 ml of dry diethyl ether were added. The mixture was stirred for about 3.5 hours at -70° C., and then allowed to warm to -5° C. Approximately 100 ml of 1N hydrochloric acid were added and the reaction mixture was stirred at 0° C. for 15 minutes. The layers were separated and the aqueous layer was extracted with one liter of ether. The organic extracts were combined, dried over magnesium sulfate, and evaporated in vacuo. The resulting oil was held at 0° C. overnight at which time an orange solid had formed. Approximately 4.6 g of this solid was recovered and identified by proton NMR to be the desired subtitle carboxaldehyde intermediate. The carboxaldehyde intermediate was used without further purification.

Workup

  1. stirringThe mixture was stirred for about 3.5 hours at -70° C.
  2. stirringthe reaction mixture was stirred at 0° C. for 15 minutes
  3. customThe layers were separated
  4. extractionthe aqueous layer was extracted with one liter of ether
  5. dry with materialdried over magnesium sulfate
  6. customevaporated in vacuo
  7. waitThe resulting oil was held at 0° C. overnight at which time
  8. customan orange solid had formed
  9. customApproximately 4.6 g of this solid was recovered
  10. customThe carboxaldehyde intermediate was used without further purification

Sources & evidence

ORD record
ord-e0cbdbb08e294e85a9c86f78d9afc037
Source dataset
uspto-grants-1987_04
Patent number
US04659717

Reaction notes

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