Dimethylformamide dimethyl acetal → Formononetin

HRID 1602674Notes

Reaction equation

HRID 1602674 reaction equation
CO[CH:3]([O:7][CH3:8])N(C)C.O[C:10]1[CH:15]=[C:14]([OH:16])[CH:13]=C[C:11]=1[C:17]([CH2:19][C:20]1[CH:25]=[CH:24][C:23]([O:26][CH3:27])=[CH:22][CH:21]=1)=[O:18]>C1C=CC=CC=1>[CH3:27][O:26][C:23]1[CH:24]=[CH:25][C:20]([C:19]2[C:17](=[O:18])[C:11]3[CH:10]=[CH:15][C:14]([OH:16])=[CH:13][C:3]=3[O:7][CH:8]=2)=[CH:21][CH:22]=1

Participants

4

Reactant 2

HCID 78373Dimethylformamide dimethyl acetal2×HCID 259632Ononetin

Product 1

HCID 5280378FormononetinYield 85%

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent2×

Procedure

Another known approach used for the synthesis of formononetin is the general method involving the addition of one carbon to 2-hydroxydeoxybenzoins and their cyclization to form isoflavones. The method introduced by Andrew Pelter (Pelter, Andrew, et al., Synthesis, 5:326 (1976)) involves the reaction of 2-hydroxydeoxybenzoins with N,N-dimethylformamide dimethylacetal (dimethoxydimethyl aminomethane) (two equivalents) in dry benzene. Refluxing a mixture of 2,4-dihydroxy-4'-methoxydeoxybenzoin with N,N-dimethylformamide dimethyl acetal in dry benzene for 4 hours gave formononetin in 85% yield. However, the use of the expensive reagent, N,N-dimethylformamide dimethyl acetal and dry benzene as solvent makes this an unattractive method for the commercial production of formononetin.

Workup

  1. additionThe method introduced by Andrew Pelter (Pelter, Andrew, et al., Synthesis, 5:326 (1976))
  2. temperatureRefluxing

Sources & evidence

ORD record
ord-558be4afb2f74a10a6f4c31552fa4176
Source dataset
uspto-grants-1999_11
Patent number
US05981775

Reaction notes

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