Dichloromethane → [(1-Benzopyran-4-yloxy)methyl]acetic Acid Ethyl Ester

HRID 2053623

Reaction equation

HRID 2053623 reaction equation
[O:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH:4]([OH:11])[CH2:3][CH2:2]1.[N+](=[CH:14][C:15]([O:17][CH2:18][CH3:19])=[O:16])=[N-].Cl[CH2:21]Cl>CCCCCCC.CC(O)=O.CC(O)=O.CC(O)=O.CC(O)=O.[Rh].[Rh]>[CH2:18]([O:17][C:15](=[O:16])[CH2:14][CH2:21][O:11][C:4]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:10]=2[O:1][CH2:2][CH:3]=1)[CH3:19]

Participants

6

Reactant 3

HCID 6344DichloromethaneHCID 12192Ethyl diazoacetateHCID 92890Chroman-4-ol

Product 1

HCID 68569392[(1-Benzopyran-4-yloxy)methyl]acetic Acid Ethyl Ester

Reagents, catalysts & solvents 2

HCID 423677Acetic acid, rhodium salt (4:2)CatalystHCID 8900HeptaneSolvent

Procedure

To a solution of 4-chromanol (1.5 g, 10.0 mmol) in dichloromethane (20 mL) is added rhodium (II) acetate dimer (10 mg) followed by ethyl diazoacetate (0.95 mL, 9.0 mmol). The reaction mixture is stirred at rt for 30 min. The reaction mixture is diluted with heptane, filtered through celite, and the filtrate is evaporated and the residue purified by chromatography on silica gel; elution with EtOAc:dichloromethane:hexane (10:20:70) gives 1.81 g of the product 475. 1H NMR (CDCl3) δ 7.35 (dd, 1H), 7.22 (dt, 1H), 6.90 (t, 1H), 6.84 (d, 1H), 4.56 (m, 1H), 4.36 (dd, 1H), 4.29 (dd, 1H), 4.23 (q, 2H), 4.19 (s, 2H), 2.18 (m, 1H), 2.05 (m, 1H), 1.30 (t, 3H); MS: m/z 236 (M++1).

Workup

  1. filtrationfiltered through celite
  2. customthe filtrate is evaporated
  3. customthe residue purified by chromatography on silica gel
  4. washelution with EtOAc:dichloromethane:hexane (10:20:70)

Sources & evidence

ORD record
ord-f2861f80ef71448e9b57d8d7df0715af
Source dataset
uspto-grants-2008_02
Patent number
US07326792B2

Linked notes

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