3-Chlorothiophene → 2-Acetyl-3-chlorothiophene

HRID 2362261Notes

Reaction equation

HRID 2362261 reaction equation
[Cl:1][C:2]1[CH:6]=[CH:5][S:4][CH:3]=1.[Li]CCCC.CON(C)[C:15](=[O:17])[CH3:16]>C1COCC1.[Cl-].[Na+].O>[Cl:1][C:2]1[CH:6]=[CH:5][S:4][C:3]=1[C:15](=[O:17])[CH3:16]

Participants

6

Conditions

Temperature
-10 °C

Procedure

To a solution of 3-chlorothiophene (4.80 g, 40.48 mmol) in THF (50 mL) was added BuLi (2.5N in hexane, 17.9 mL) at −30° C. After addition, the mixture was stirred for 30 min at −10° C., and then cooled to −45° C. N-methoxy-N-methyl acetamide (55.0 g, 48.8 mmol) was added and allowed to warm to room temperature during 40 min and maintained for an additional 20 min. Brine (80 mL) was added to quench the reaction, extracted with EA (60 mL×3). The combined organic layers were dried over anhydrous Na2SO4, filtered, concentrated to afford 24-1 (˜80% pure) as a yellow oil (6.80 g) which used for the next step directly.

Workup

  1. additionAfter addition
  2. temperaturecooled to −45° C
  3. temperatureto warm to room temperature during 40 min
  4. temperaturemaintained for an additional 20 min
  5. customto quench
  6. customthe reaction
  7. extractionextracted with EA (60 mL×3)
  8. dry with materialThe combined organic layers were dried over anhydrous Na2SO4
  9. filtrationfiltered
  10. concentrationconcentrated

Sources & evidence

ORD record
ord-9c8e93d6d29c4554b938f8d28c682fcb
Source dataset
uspto-grants-2014_04
Patent number
US08691816B2

Reaction notes

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