Oxalyl chloride → 8-Fluoro-2,3-dihydro-4H-1-benzopyran-4-one

HRID 600421Notes

Reaction equation

HRID 600421 reaction equation
C(Cl)(=O)C(Cl)=O.[F:7][C:8]1[CH:19]=[CH:18][CH:17]=[CH:16][C:9]=1[O:10][CH2:11][CH2:12][C:13]([OH:15])=O.[Cl-].[Al+3].[Cl-].[Cl-]>CN(C=O)C.C(Cl)Cl>[F:7][C:8]1[CH:19]=[CH:18][CH:17]=[C:16]2[C:9]=1[O:10][CH2:11][CH2:12][C:13]2=[O:15]

Participants

6

Reactant 3

HCID 65578Oxalyl chlorideHCID 15457213-(2-fluorophenoxy)propanoic AcidHCID 6451240Aluminum(III) Chloride

Product 1

HCID 139538178-Fluoro-2,3-dihydro-4H-1-benzopyran-4-oneYield 98%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideCatalystHCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

Oxalyl chloride (8.79 mL) and one drop of DMF were added to an ice cold solution of 3-(2-fluorophenoxy)propanoic acid (9.27 g) in methylene chloride (50 mL). The solution was stirred at 0° C. for two hours, aluminum chloride (7.39 g, 55.42 mM) was added and the solution was stirred for 16 hours at room temperature. The mixture was poured onto ice water, and extracted three times with methylene chloride. The combined organics were washed with 0.5M NaOH and brine, dried, evaporated, and purified by column chromatography (eluting with 20% EtOAc/Hex) to give 8-fluorochroman-4-one (3) (8.20 g, 98%).

Workup

  1. stirringthe solution was stirred for 16 hours at room temperature
  2. additionThe mixture was poured onto ice water
  3. extractionextracted three times with methylene chloride
  4. washThe combined organics were washed with 0.5M NaOH and brine
  5. customdried
  6. customevaporated
  7. custompurified by column chromatography (eluting with 20% EtOAc/Hex)

Sources & evidence

ORD record
ord-f0e520929165432c8e283d547cb1f46f
Source dataset
uspto-grants-2011_03
Patent number
US07902187B2

Reaction notes

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