Hydrochloric Acid → 1-(5-Bromothiophen-2-yl)-4,4-difluorobutane-1,3-dione

HRID 129209

反応式

HRID 129209 の反応式
[F:1][CH:2]([F:8])[C:3]([O:5]CC)=O.C[O-].[Na+].[C:12]([C:15]1[S:16][C:17]([Br:20])=[CH:18][CH:19]=1)(=[O:14])[CH3:13].Cl>CCOCC.C1COCC1>[F:8][CH:2]([F:1])[C:3](=[O:5])[CH2:13][C:12]([C:15]1[S:16][C:17]([Br:20])=[CH:18][CH:19]=1)=[O:14]

参加物

7

反応物 4

HCID 313Hydrochloric AcidHCID 9961Ethyl difluoroacetateHCID 793352-Acetyl-5-bromothiopheneHCID 10942334Sodium Methoxide

生成物 1

HCID 189203811-(5-Bromothiophen-2-yl)-4,4-difluorobutane-1,3-dione収率 73.3%

試薬・触媒・溶媒 2

HCID 3283Diethyl Ether溶媒HCID 8028Tetrahydrofuran溶媒

実験手順

Ethyl difluoroacetate (2.43 g, 19.6 mmol) was placed in a 100 mL round bottom flask, and dissolved in ether (15 mL). To the stirred solution was added 25 weight % sodium methoxide (4.23 g, 19.5 mmol) followed by 2-acetyl-5-bromothiophene (3.59 g, 17.5 mmol). After two hours a precipitate formed and THF (15 mL) was added to allow stirring to continue. The reaction was stirred at room temperature 6.2 hours, then treated with 3N HCl (20 mL). The organic layer was collected and washed with brine, dried over MgSO4, and concentrated in vacuo to give a yellow oil which was crystallized from methylene chloride/isooctane to give yellow needles (3.63 g, mp 83.5°-85° C., 73% ). 1H NMR (CDCl3) 300 MHz 14.60 (br s, 1H), 7.53 (d, J=4.0 Hz, 1H), 7.15 (d, J=4.0 Hz, 1H), 7.19 (m, 1H), 6.32 (s, 1H), 6.04 (t, J=54.2 Hz, 1H); 19F NMR (CDCl3) 300 MHz: -127.00 (d) ; M+282.

後処理

  1. customAfter two hours a precipitate formed
  2. stirringThe reaction was stirred at room temperature 6.2 hours
  3. customThe organic layer was collected
  4. washwashed with brine
  5. dry with materialdried over MgSO4
  6. concentrationconcentrated in vacuo
  7. customto give a yellow oil which
  8. customwas crystallized from methylene chloride/isooctane

出典と根拠

ORDレコード
ord-ab8018c562ad443086ff6756f78cd16c
出典データセット
uspto-grants-1995_11
特許番号
US05466823

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