2-Chlorothiophene → 2-Acetyl-5-chlorothiophene

HRID 1443317Notes

Reaction equation

HRID 1443317 reaction equation
[C:1](OC(=O)C)(=[O:3])[CH3:2].[Cl:8][C:9]1[S:10][CH:11]=[CH:12][CH:13]=1>>[C:1]([C:11]1[S:10][C:9]([Cl:8])=[CH:13][CH:12]=1)(=[O:3])[CH3:2]

Participants

3

Reactant 2

HCID 72992-ChlorothiopheneHCID 7918Acetic Anhydride

Product 1

HCID 805722-Acetyl-5-chlorothiopheneYield 52%

Procedure

5.9 g of activated clay (product of Nacalai Tesque, Inc.) and 25.5 g (0.25 moles) of acetic anhydride were introduced into a 100 ml 4-necked flask equipped with a stirrer, condenser, thermometer, and dropping funnel. 29.6 g (0.25 moles) of 2-chlorothiophene was added dropwise at 45° C. to 55° C. over 1 hour. After the dropwise addition, the reaction was allowed to proceed at 50° C. for 72 hours. After the reaction, the activated clay was separated by filtration to give a dark brown filtrate. The filtrate was subjected to distillation to remove unreacted 2-chlorothiophene, acetic anhydride, and by-product acetic acid, thus giving 20.9 g (0.13 moles) of 2-acetyl-5-chlorothiophene. The yield of 2-acetyl-5-chlorothiophene was 52% based on 2-chlorothiophene. The 3-isomer content was determined in the same manner as in Example 1. The 3-acetyl-5-chlorothiophene content of the resulting 2-acetyl-5-chlorothiophene product was 0.5 wt. %.

Workup

  1. customequipped with a stirrer, condenser
  2. additionAfter the dropwise addition
  3. customAfter the reaction
  4. customthe activated clay was separated by filtration
  5. customto give a dark brown filtrate
  6. distillationThe filtrate was subjected to distillation
  7. customto remove unreacted 2-chlorothiophene, acetic anhydride, and by-product acetic acid

Sources & evidence

ORD record
ord-6468d0c51e3944e09e85f37433cb0def
Source dataset
uspto-grants-2010_02
Patent number
US07659411B2

Reaction notes

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