Benzyl Bromide → Benzyl 6,7-dichloro-4H-1-benzopyran-4-carboxylate

HRID 487215Notes

Reaction equation

HRID 487215 reaction equation
[Cl:1][C:2]1[C:3]([Cl:15])=[CH:4][C:5]2[O:10][CH:9]=[CH:8][CH:7]([C:11]([OH:13])=[O:12])[C:6]=2[CH:14]=1.[CH2:16](Br)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1.C(=O)(O)[O-].[Na+]>ClCCl>[Cl:1][C:2]1[C:3]([Cl:15])=[CH:4][C:5]2[O:10][CH:9]=[CH:8][CH:7]([C:11]([O:13][CH2:16][C:17]3[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=3)=[O:12])[C:6]=2[CH:14]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 516892Sodium BicarbonateHCID 149865616,7-dichloro-4H-1-benzopyran-4-carboxylic acid

Product 1

HCID 19094451Benzyl 6,7-dichloro-4H-1-benzopyran-4-carboxylate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A mixture of 6,7-dichloro-4H-1-benzopyran-4-carboxylic acid (16.8 gm), tetra (N-butyl)ammonium hydrogensulfate (23 gm), benzyl bromide (9.7 mL), saturated sodium bicarbonate (100 mL) and dichloromethane (100 mL) were stirred vigorously at room temperature for 14 hours, then diluted with dichloromethane, and the organic layer separated, washed with saturated sodium bicarbonate, water, brine, dried (MgSO4), filtered and evaporated. The residue was purified by column chromatography (2:1 dichloromethane/hexanes, SiO2) to afford the title compound (11.8 gm, Rf=0.3 (2:1 dichloromethane/hexanes, SiO2).

Workup

  1. customthe organic layer separated
  2. washwashed with saturated sodium bicarbonate, water, brine
  3. dry with materialdried (MgSO4)
  4. filtrationfiltered
  5. customevaporated
  6. customThe residue was purified by column chromatography (2:1 dichloromethane/hexanes, SiO2)

Sources & evidence

ORD record
ord-2173650d53ea4f079ddc1f7e2ac811d0
Source dataset
uspto-grants-1994_03
Patent number
US05294635

Reaction notes

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