Acetic Acid → ethyl 3,4-dihydro-1H-2-benzopyran-1-acetate

HRID 368859ノート

反応式

HRID 368859 の反応式
[OH:1][CH2:2][CH2:3][C:4]1[CH:16]=[CH:15][CH:14]=[CH:13][C:5]=1[CH:6]=[CH:7][C:8]([O:10][CH2:11][CH3:12])=[O:9].CC(C)([O-])C.[K+].C(O)(=O)C>C1COCC1>[CH:6]1([CH2:7][C:8]([O:10][CH2:11][CH3:12])=[O:9])[C:5]2[C:4](=[CH:16][CH:15]=[CH:14][CH:13]=2)[CH2:3][CH2:2][O:1]1

参加物

5

反応物 3

HCID 176Acetic AcidHCID 23665647Potassium tert-butoxideHCID 54089289Ethyl 2-(2-hydroxyethyl)cinnamate2 回

生成物 1

HCID 10822798ethyl 3,4-dihydro-1H-2-benzopyran-1-acetate

試薬・触媒・溶媒 1

HCID 8028Tetrahydrofuran溶媒2 回

実験手順

Ethyl 2-(2-hydroxyethyl)cinnamate (CXXX, EXAMPLE 112, theoretically 2.40 moles) is dissolved in THF (2.4 liters) and cooled to 0°. Potassium t-butoxide (5 mol %, 120 ml of a 1 molar THF solution) is added via syringe. After 5 min HPLC shows the cyclization is completed. Acetic acid (6 mol %, 8.2 ml, 144 mmol) is added. The slurry is filtered through approximately 300 g of 200 mesh silica gel. The solvent is Diatomaceous earth (100 g) is added followed by hexane (4.5 liters). This slurry is filtered through 200 mesh silica gel (400 g), washing with THF/hexane (1/9) until TLC shows no remaining product. Solvent removal gives the title compound. This material is filtered through silica gel more carefully, giving an analytical sample of the title compound, NMR (300 MHz, CDCl3) 7.1-7.2, 7.05, 5.26, 4.23, 4.12, 3.83, 3.0-2.7, 1.28; high resolution MS calculated for 220.1099, found 220.1105.

後処理

  1. temperaturecooled to 0°
  2. filtrationThe slurry is filtered through approximately 300 g of 200 mesh silica gel
  3. additionis added
  4. filtrationThis slurry is filtered through 200 mesh silica gel (400 g)
  5. washwashing with THF/hexane (1/9) until TLC
  6. customSolvent removal

出典と根拠

ORDレコード
ord-4106ba3ccb894ad696c3bcb753dbe41a
出典データセット
uspto-grants-2000_10
特許番号
US06133446

反応ノート

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