Hydrochloric Acid → 2,2-dimethyl-3,4-dihydro-2H-1-benzopyran-7-ol

HRID 1427839

反応式

HRID 1427839 の反応式
[OH:1][C:2]1[CH:11]=[C:10]2[C:5]([C:6](=O)[CH2:7][C:8]([CH3:13])([CH3:12])[O:9]2)=[CH:4][CH:3]=1.Cl>CO.[Zn]>[CH3:12][C:8]1([CH3:13])[CH2:7][CH2:6][C:5]2[C:10](=[CH:11][C:2]([OH:1])=[CH:3][CH:4]=2)[O:9]1

参加物

5

反応物 2

HCID 313Hydrochloric AcidHCID 6009027-hydroxy-2,2-dimethyl-3,4-dihydro-2H-1-benzopyran-4-one

生成物 1

HCID 110412812,2-dimethyl-3,4-dihydro-2H-1-benzopyran-7-ol収率 62.6%

試薬・触媒・溶媒 2

HCID 23994Zinc触媒HCID 887Methanol溶媒

反応条件

温度
0 °C

実験手順

A mixture of 7-hydroxy-2,2-dimethylchroman-4-one (500 mg, 2.60 mmol) and HCl (conc. 10 mL) in MeOH (30 mL) was stirred at 0° C. for 10 min, then zinc power (300 mg) was added slowly. After stirring at room temperature for 16 hrs, the solvents were removed under reduced pressure and the mixture was extracted with EtOAc (150×3 mL). The combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated. The residue was purified by reverse phase column flash (28%-35% MeCN in 0.5% NH4HCO3) to give target product of 2,2-dimethylchroman-7-ol (290 mg, 62%) as a brown yellow solid. LCMS (ESI) m/z: 177.1 [M−H]+; 1H-NMR (500 MHz, CDCl3): δ 6.89 (d, J=8.0 Hz, 1H), 6.34 (dd, J=8.5, 2.5 Hz, 1H), 6.27 (d, J=2.5 Hz, 1H), 4.70 (s, 1H), 2.69 (t, J=13.5, 7.0 Hz, 2H), 1.77 (t, J=13.5, 7.0 Hz, 2H), 1.32 (s, 6H).

後処理

  1. stirringAfter stirring at room temperature for 16 hrs
  2. customthe solvents were removed under reduced pressure
  3. extractionthe mixture was extracted with EtOAc (150×3 mL)
  4. washThe combined organic layers were washed with brine
  5. dry with materialdried over Na2SO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe residue was purified by reverse phase column flash (28%-35% MeCN in 0.5% NH4HCO3)

出典と根拠

ORDレコード
ord-d9fc11a0594140398409073dc59cbdca
出典データセット
uspto-grants-2015_01
特許番号
US08933236B2

関連ノート

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