Methanol → (alphaS)-4-Chloro-alpha-(1-methylethyl)benzeneacetic acid

HRID 1416091

反応式

HRID 1416091 の反応式
O=O.[Cl:3][C:4]1[CH:9]=[CH:8][C:7]([C:10](=[C:14]([CH3:16])[CH3:15])[C:11]([OH:13])=[O:12])=[CH:6][CH:5]=1.CO>O1CCCC1.[Rh]>[Cl:3][C:4]1[CH:5]=[CH:6][C:7]([C@H:10]([CH:14]([CH3:16])[CH3:15])[C:11]([OH:13])=[O:12])=[CH:8][CH:9]=1

参加物

6

反応物 3

HCID 887MethanolHCID 977OxygenHCID 139522262-(p-Chlorophenyl)-3-methylcrotonic acid

生成物 1

HCID 854132(alphaS)-4-Chloro-alpha-(1-methylethyl)benzeneacetic acid収率 96%

試薬・触媒・溶媒 2

HCID 23948Rhodium触媒HCID 8028Tetrahydrofuran溶媒2 回

実験手順

Rhodium-catalyzed hydrogenation. --A catalyst solution was prepared in a glove box (O2 content <1 ppm) by dissolving 0.0482 g (0.1 19 mmol) of [Rh(COD)2 ]BF4 and 0.0858 g (0.1 19 mmol) of (R,S)-BPPFA-EPIP in 20 ml of tetrahydrofuran and stirring at 20° for 15 minutes. Then, 5.0 g (23.74 mmol) of 2-(p-chlorophenyl)-3-methylcrotonic acid, 13 ml of methanol, 33 ml of tetrahydrofuran were placed in a 185 ml autoclave and the catalyst solution prepared above was added. The autoclave was sealed and the hydrogenation was carried out at 20° while stirring and under a constant pressure of 50 bar. The conversion was 100% after 18 hours. The hydrogenation solution was evaporated at 50°/20 mbar and the residue was distilled in a bulb tube oven at 150°/0.2 mbar. There were obtained 4.8 g (96%) of (S)-2-(p-chlorophenyl)-3-methylbutyric acid as a colorless oil which crystallized out at RT; chemical purity 99.9 GC area %; 97.6% ee.

後処理

  1. customthe catalyst solution prepared
  2. additionabove was added
  3. customThe autoclave was sealed
  4. customwas carried out at 20°
  5. stirringwhile stirring and under a constant pressure of 50 bar
  6. customafter 18 hours
  7. customThe hydrogenation solution was evaporated at 50°/20 mbar
  8. distillationthe residue was distilled in a bulb tube oven at 150°/0.2 mbar

出典と根拠

ORDレコード
ord-4fff1c29755446fea71d6fc4811496f7
出典データセット
uspto-grants-1999_06
特許番号
US05910606

関連ノート

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