4-Hydroxycoumarin → 4-Hydroxy-3-benzylcoumarin

HRID 983497Notes

Reaction equation

HRID 983497 reaction equation
[OH:1][C:2]1[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[O:5][C:4](=[O:12])[CH:3]=1>C(N(CC)CC)C.C(O)=O>[CH2:2]([C:3]1[C:4](=[O:12])[O:5][C:6]2[C:11]([C:2]=1[OH:1])=[CH:10][CH:9]=[CH:8][CH:7]=2)[C:11]1[CH:6]=[CH:7][CH:8]=[CH:9][CH:10]=1

Participants

4

Reactant 1

HCID 546829304-Hydroxycoumarin

Product 1

HCID 546861124-Hydroxy-3-benzylcoumarin

Reagents, catalysts & solvents 2

HCID 284Formic AcidSolventHCID 8471TriethylamineSolvent

Procedure

Scheme 2 provides an alternative synthesis of C-3 substituted 4-hydroxycoumarins when R1 is aryl groups. 4-hydroxycoumarin and an aromatic aldehyde can be heated in a mixture of triethylamine and formic acid (2:5 molar ratio) to give 3-benzyl-4-hydroxycoumarin, which was in turn treated with 2.2 eq. of BuLi and quenched with carbon dioxide to give coumarin substituted phenyl-acetic acid. Corresponding esters can be obtained by treating the acid with various alcohols in the presence of concentrated sulfuric acid.

Workup

  1. customScheme 2 provides

Sources & evidence

ORD record
ord-ef0d0f27a00c48c888d19e3b1f2d8dcc
Source dataset
uspto-grants-2005_03
Patent number
US06864279B2

Reaction notes

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