Ethanol → Methyl 7-hydroxy-2-methyl-2,3-dihydro-1,4-benzodioxine-2-carboxylate

HRID 1866212ノート

反応式

HRID 1866212 の反応式
C([C:4]1[CH:5]=[CH:6][C:7]2[O:11][C@:10]([CH2:16]C)([C:12]([O:14][CH3:15])=[O:13])[CH2:9][C:8]=2[CH:18]=1)(=O)C.[OH-:19].[K+].B(Br)(Br)Br.C[Si](C=[N+]=[N-])(C)C.C([OH:34])C>ClCCl.C1C=CC=CC=1.CO>[CH3:9][C:10]1([C:12]([O:14][CH3:15])=[O:13])[O:11][C:7]2[CH:8]=[C:18]([OH:34])[CH:4]=[CH:5][C:6]=2[O:19][CH2:16]1

参加物

8

反応物 5

HCID 702EthanolHCID 14797Potassium HydroxideHCID 25134Boron tribromideHCID 167693TrimethylsilyldiazomethaneHCID 57978455methyl (2S)-5-acetyl-2-ethyl-2,3-dihydro-benzofuran-2-carboxylate

生成物 1

HCID 57978461Methyl 7-hydroxy-2-methyl-2,3-dihydro-1,4-benzodioxine-2-carboxylate

試薬・触媒・溶媒 2

HCID 6344Dichloromethane溶媒HCID 21927730Benzene methanol溶媒

実験手順

The product from Step 5 (0.6 g, 2.9 mmol) was treated with 2 N KOH in ethanol under reflux for 4 h. Removal of ethanol and acidification of the residue with 2 N HCl gave the crude acid, which was dissolved in dichloromethane (mL) and treated with boron tribromide (1 M in hexane, mL, mmol) at 0 C for 1 h. The reaction was quenched with water and extracted with dichloromethane. The combined extracts were washed with brine and dried over MgSO4. Removal of solvents gave a residue which was taken up in 7:1 benzene/methanol and treated with excess trimethylsilyldiazo methane (1 m in hexane). Removal of solvents and purification of the residue by chromatography on silica gel afforded 0.48 (75% yield) of the title compound as an oil.

後処理

  1. temperatureunder reflux for 4 h
  2. customRemoval of ethanol and acidification of the residue with 2 N HCl
  3. customgave the crude acid, which
  4. customThe reaction was quenched with water
  5. extractionextracted with dichloromethane
  6. washThe combined extracts were washed with brine
  7. dry with materialdried over MgSO4
  8. customRemoval of solvents
  9. customgave a residue which
  10. customRemoval of solvents and purification of the residue by chromatography on silica gel

出典と根拠

ORDレコード
ord-b2c661d188944fc1b27cf9262696d82d
出典データセット
uspto-grants-2009_12
特許番号
US07629372B2

反応ノート

読み込み中…