Acetic Acid → Methyl 4-bromo-3-methylthiophene-2-carboxylate

HRID 1465948노트

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HRID 1465948 반응식
C[Si](C=[N+]=[N-])(C)C.[CH3:8]COCC.[Br:13][C:14]1[C:15]([CH3:22])=[C:16]([C:19]([OH:21])=[O:20])[S:17][CH:18]=1.C(O)(=O)C>CO.O1CCCC1>[CH3:8][O:20][C:19]([C:16]1[S:17][CH:18]=[C:14]([Br:13])[C:15]=1[CH3:22])=[O:21]

참가 물질

7

반응물 4

HCID 176Acetic AcidHCID 3283Diethyl EtherHCID 167693Trimethylsilyldiazomethane2회HCID 27570734-Bromo-3-methylthiophenecarboxylic acid

생성물 1

HCID 59212115Methyl 4-bromo-3-methylthiophene-2-carboxylate수율 92.6%

시약·촉매·용매 2

HCID 887Methanol용매HCID 8028Tetrahydrofuran용매

실험 절차

The (trimethylsilyl)diazomethane solution in ether (2.0 M, 41.2 mL, 82.3 mmol) was added dropwise to a solution of 4-bromo-3-methyl-thiophene-2-carboxylic acid (13.0 g, 58.8 mmol, purchased from Oakwood Products) in methanol (50 mL) and tetrahydrofuran (50 mL) at ambient temperature. After the reaction mixture was stirred at ambient temperature for 30 min, acetic acid was added to decompose the excess (trimethylsilyl)diazomethane until the yellow color disappeared. Most of the solvent was evaporated and ethyl acetate was added. The organic solution was washed with saturated sodium bicarbonate solution and brine, dried over anhydrous sodium sulfate and concentrated. The crude product was purified by flash chromatography eluting from silica gel with a gradient of 0-50% ethyl acetate in hexanes to produce 12.8 g of a white solid. 1H NMR (CDCl3, 200 MHz): δ=7.40 (s, 1H), 3.87 (s, 3H), and 2.54 (s, 3H).

후처리

  1. customMost of the solvent was evaporated
  2. additionethyl acetate was added
  3. washThe organic solution was washed with saturated sodium bicarbonate solution and brine
  4. dry with materialdried over anhydrous sodium sulfate
  5. concentrationconcentrated
  6. customThe crude product was purified by flash chromatography
  7. washeluting from silica gel with a gradient of 0-50% ethyl acetate in hexanes

출처 및 근거

ORD 기록
ord-11931a0ecc194d58ad485c2271dae191
출처 데이터셋
uspto-grants-2015_04
특허 번호
US09000006B2

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