Isobutyric Acid → 2,2-Dimethyl-3-phenylpropanoic acid

HRID 54230ノート

反応式

HRID 54230 の反応式
[H-].[Na+].C(NC(C)C)(C)C.[C:10]([OH:15])(=[O:14])[CH:11]([CH3:13])[CH3:12].C([Li])CCC.[CH2:21](Br)[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1>CCCCCC.O.O1CCCC1>[CH3:12][C:11]([CH3:13])([CH2:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)[C:10]([OH:15])=[O:14]

参加物

9

反応物 5

HCID 6590Isobutyric AcidHCID 7498Benzyl BromideHCID 7912DiisopropylamineHCID 24758Sodium hydrideHCID 178418339Butyllithium

生成物 1

HCID 218802,2-Dimethyl-3-phenylpropanoic acid収率 15%

試薬・触媒・溶媒 3

HCID 962Water溶媒HCID 8028Tetrahydrofuran溶媒HCID 8058Hexane溶媒

反応条件

温度
0 °C

実験手順

To a mixture of 1.23 g (41.0 mmol) of 80% sodium hydride and 50 mL of anhydrous tetrahydrofuran under a nitrogen atmosphere, was added 3.88 g (38.3 mmol) of diisopropylamine and then 3.3 g (37.5 mmol) of isobutyric acid. After heating at reflux for 5 minutes and cooling to 0° C., 15 mL (37.5 mmol) of 2.5M n-butyllithium in hexane was added. The mixture was warmed to 35° C. for 30 min, cooled to 0° C. and 6.40 g (37.5 mmol) of benzyl bromide added. The mixture was stirred for 30 minutes at 0° C., then warmed to 35° C. for one hour and recooled to 0° C. Water was added and the aqueous layer extracted with diethyl ether, acidified with 6N aqueous HCl and extracted with diethyl ether. The organic layer was dried and concentrated to provide 4.0 g of crude product. Chromatography on silica gel using 10% methanol/methylene chloride afforded 1.0 g of pure 2,2-dimethyl-3-phenylpropionic acid, m/e 185 (M+Li).

後処理

  1. temperatureAfter heating
  2. temperatureat reflux for 5 minutes
  3. temperatureThe mixture was warmed to 35° C. for 30 min
  4. temperaturecooled to 0° C.
  5. temperaturewarmed to 35° C. for one hour
  6. customrecooled to 0° C
  7. extractionthe aqueous layer extracted with diethyl ether
  8. extractionextracted with diethyl ether
  9. customThe organic layer was dried
  10. concentrationconcentrated
  11. customto provide 4.0 g of crude product

出典と根拠

ORDレコード
ord-f054f2770ff34f30b310220b4e49049a
出典データセット
uspto-grants-1997_04
特許番号
US05622949

反応ノート

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