Carbon Dioxide → 5-Methyl-2,3-dihydro-1,4-benzodioxine-6-carboxylic acid

HRID 260718ノート

反応式

HRID 260718 の反応式
Br[C:2]1[CH:11]=[CH:10][C:5]2[O:6][CH2:7][CH2:8][O:9][C:4]=2[C:3]=1[CH3:12].C([Li])CCC.CCCCCC.[C:24](=[O:26])=[O:25]>O1CCCC1.O>[CH3:12][C:3]1[C:4]2[O:9][CH2:8][CH2:7][O:6][C:5]=2[CH:10]=[CH:11][C:2]=1[C:24]([OH:26])=[O:25]

参加物

7

反応物 4

HCID 280Carbon Dioxide2 回HCID 8058HexaneHCID 124645276-Bromo-5-methyl-2,3-dihydro-1,4-benzodioxineHCID 178418339Butyllithium

生成物 1

HCID 107029595-Methyl-2,3-dihydro-1,4-benzodioxine-6-carboxylic acid収率 77%

試薬・触媒・溶媒 2

HCID 962Water溶媒HCID 8028Tetrahydrofuran溶媒

反応条件

温度
-78 °C

実験手順

In 300 ml of dry tetrahydrofuran, was dissolved 32.0 g of 6-bromo-5-methyl-1,4-benzodioxane and after cooling the solution to -78° C., 96.7 ml of n-butyl lithium (n-hexane solution)was added dropwise over 20 minutes or more. After stirring at the same temperature for 1.5 hours, the reaction mixture was poured onto crushed dry ice and dry ice was sublimated while stirring. Water was added to the -mixture and the tetrahydrofuran was removed under reduced pressure. The resulting alkaline aqueous solution was washed with methylene chloride and adjusted to pH 3 with a 5% hydrochloric acid, and the precipitated crystals were collected by filtration and dried to obtain 20.9 g of 5-methyl-1,4-benzodioxan-6-carboxylic acid (yield: 77%).

後処理

  1. additionthe reaction mixture was poured
  2. stirringwhile stirring
  3. customthe tetrahydrofuran was removed under reduced pressure
  4. washThe resulting alkaline aqueous solution was washed with methylene chloride
  5. filtrationthe precipitated crystals were collected by filtration
  6. customdried

出典と根拠

ORDレコード
ord-266f65c38c6d41cfbdb52275a0f7a04a
出典データセット
uspto-grants-1996_06
特許番号
US05530021

反応ノート

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