N,N,N',N'-Tetramethylmethanediamine → 2',4'-Dichloro-3-methylene flavanone

HRID 1733285Notes

Reaction equation

HRID 1733285 reaction equation
[Cl:1][C:2]1[CH:18]=[C:17]([Cl:19])[CH:16]=[CH:15][C:3]=1[CH:4]1[CH2:13][C:12](=[O:14])[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[O:5]1.[CH3:20]N(CN(C)C)C.C(OC(=O)C)(=O)C>>[Cl:1][C:2]1[CH:18]=[C:17]([Cl:19])[CH:16]=[CH:15][C:3]=1[CH:4]1[C:13](=[CH2:20])[C:12](=[O:14])[C:11]2[C:6](=[CH:7][CH:8]=[CH:9][CH:10]=2)[O:5]1

Participants

4

Reactant 3

HCID 5829N,N,N',N'-TetramethylmethanediamineHCID 7918Acetic AnhydrideHCID 127531732',4'-Dichloro flavanone

Product 1

HCID 127531762',4'-Dichloro-3-methylene flavanone

Procedure

A mixture of 3 g (10 mmol) of the 2',4'-dichloro flavanone and 27 ml of bis-(dimethylamino)methane was stirred at room temperature; 27 ml of acetic anhydride was added dropwise over 15 minutes. A slight temperature rise occurred. One hour later the reaction was partitioned between 200 ml of ether and 200 ml of cold H2O. The aqueous phase was separated, washed with two 250 ml portions of ether, and discarded. The combined ether extracts were washed with saturated aqueous NaHCO3 solution, dried over anhydrous Na2SO4, filtered and evaporated. The residual oil was chromatographed on 200 g of silica gel, eluting with benzene. This gave 2.5 g of 2',4'-dichloro-3-methylene flavanone, isolated as a solid, m.p. 86°-87° C.

Workup

  1. customOne hour later the reaction was partitioned between 200 ml of ether and 200 ml of cold H2O
  2. customThe aqueous phase was separated
  3. washwashed with two 250 ml portions of ether
  4. washThe combined ether extracts were washed with saturated aqueous NaHCO3 solution
  5. dry with materialdried over anhydrous Na2SO4
  6. filtrationfiltered
  7. customevaporated
  8. customThe residual oil was chromatographed on 200 g of silica gel
  9. washeluting with benzene

Sources & evidence

ORD record
ord-47bfabade6934224bfb8b57d44e9e5cf
Source dataset
uspto-grants-1980_12
Patent number
US04241069

Reaction notes

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