Sodium Hydroxide → 5-Bromo-4-methylthiophene-2-carboxylic acid

HRID 357764ノート

反応式

HRID 357764 の反応式
[Br:1][C:2]1[S:6][C:5]([CH:7]=[O:8])=[CH:4][C:3]=1[CH3:9].P([O-])(O)(O)=[O:11].[Na+].Cl([O-])=O.[Na+].[OH-].[Na+]>C(#N)C.O.OO>[Br:1][C:2]1[S:6][C:5]([C:7]([OH:11])=[O:8])=[CH:4][C:3]=1[CH3:9]

参加物

8

反応物 4

HCID 14798Sodium HydroxideHCID 164141925-Bromo-4-methylthiophene-2-carbaldehydeHCID 23668197Sodium ChloriteHCID 23672064Monosodium phosphate

生成物 1

HCID 218994595-Bromo-4-methylthiophene-2-carboxylic acid収率 250.9%

試薬・触媒・溶媒 3

HCID 784Hydrogen Peroxide溶媒HCID 962Water溶媒2 回HCID 6342Acetonitrile溶媒

実験手順

Aluminum chloride (14.6 g) was added portionwise to 2-bromo-3-methylthiophene (8.85 g) and dichloromethyl methyl ether (6.27 g) in dichloromethane (100 ml) under ice-cooling. The mixture was stirred at room temperature for 1 hour and poured into ice water, acidified with 1N hydrochloric acid and extracted with ethyl acetate. The extract was washed with aqueous sodium chloride, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to give 5-bromo-4-methyl-2-thiophenecarbaldehyde (8.0 g). 5-Bromo-4-methyl-2-thiophenecarbaldehyde (6.18 g) was dissolved in acetonitrile (100 ml), and sodium dihydrogen phosphate (1.3 g) in water (20 ml) and 30% aqueous hydrogen peroxide (3.8 ml) were added. Further sodium chlorite (4.07 g) in water (50 ml) was added dropwise under ice-cooling. The mixture was stirred at room temperature for 2 hours, alkalified with 1N aqueous sodium hydroxide and washed with diethyl ether. The aqueous layer was acidified with 1N hydrochloric acid and extracted with ethyl acetate. The extract was dried over anhydrous magnesium sulfate and concentrated under reduced pressure to give 5-bromo-4-methyl-2-thiophenecarboxylic acid (6.01 g) as crystals.

後処理

  1. temperaturecooling
  2. washwashed with diethyl ether
  3. extractionextracted with ethyl acetate
  4. dry with materialThe extract was dried over anhydrous magnesium sulfate
  5. concentrationconcentrated under reduced pressure

出典と根拠

ORDレコード
ord-ad915164765d435e81a6df34a5500781
出典データセット
uspto-grants-1998_11
特許番号
US05840917

反応ノート

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