Acetic Anhydride → (4,5-Dimethoxypyridin-2-yl)methanol

HRID 845530ノート

反応式

HRID 845530 の反応式
[CH3:1][O:2][C:3]1[C:8]([O:9][CH3:10])=[CH:7][N+:6]([O-])=[C:5]([CH3:12])[CH:4]=1.C(OC(=O)C)(=[O:15])C>>[OH:15][CH2:12][C:5]1[CH:4]=[C:3]([O:2][CH3:1])[C:8]([O:9][CH3:10])=[CH:7][N:6]=1

参加物

3

反応物 2

HCID 7918Acetic AnhydrideHCID 151634594,5-Dimethoxy-2-methylpyridine 1-oxide

生成物 1

HCID 12468241(4,5-Dimethoxypyridin-2-yl)methanol収率 74%

反応条件

温度
80 °C

実験手順

19 g of 4,5-dimethoxy-2-methylpyridine 1-oxide are metered into 60 ml of acetic anhydride, warmed to 80° C., in the course of 30 minutes in a manner such that the temperature does not rise above 100° C. After a further 45 minutes at 85° C., excess acetic anhydride is distilled off in vacuo and the oily dark residue, which essentially consists of the intermediate 2-acetoxymethyl-4,5-dimethoxypyridine is stirred with 80 ml of 2N sodium hydroxide solution at 80° C. for 1 hour. After dilution with 80 ml of water and cooling, the mixture is extracted eight times with 100 ml of methylene chloride each time, the combined organic phases are washed twice with 1N sodium hydroxide solution, dried and concentrated and the crystalline, brownish residue is recrystallized from toluene. 14 g (74% of theory) of 2-hydroxymethyl-4,5-dimethoxy-pyridine of m.p. 122°-124° C. are obtained.

後処理

  1. customdoes not rise above 100° C
  2. distillationexcess acetic anhydride is distilled off in vacuo
  3. temperatureAfter dilution with 80 ml of water and cooling
  4. extractionthe mixture is extracted eight times with 100 ml of methylene chloride each time
  5. washthe combined organic phases are washed twice with 1N sodium hydroxide solution
  6. customdried
  7. concentrationconcentrated
  8. customthe crystalline, brownish residue is recrystallized from toluene

出典と根拠

ORDレコード
ord-3bddb7e067104a9092fc5acc7bbef97e
出典データセット
uspto-grants-1988_07
特許番号
US04758579

反応ノート

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