Hydrochloric Acid → Methyl 6-fluorochromane-4-carboxylate

HRID 2248283Notes

Reaction equation

HRID 2248283 reaction equation
[F:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH2:9][CH2:8][CH:7]([C:11]([OH:13])=[O:12])[C:6]=2[CH:14]=1.Cl.[CH3:16]O>>[F:1][C:2]1[CH:3]=[CH:4][C:5]2[O:10][CH2:9][CH2:8][CH:7]([C:11]([O:13][CH3:16])=[O:12])[C:6]=2[CH:14]=1

Participants

4

Reactant 3

HCID 313Hydrochloric AcidHCID 887MethanolHCID 139537996-Fluoro-3,4-dihydro-2H-1-benzopyran-4-carboxylic acid

Product 1

HCID 14986536Methyl 6-fluorochromane-4-carboxylate

Procedure

A solution of 8.4 g of the 6-fluoro-2,3-dihydro-4H-benzopyran-4-carboxylic acid in 580 mL of methanol was perfused with HCl gas for 5 minutes. The resulting solution was stirred at room temperature overnight. The volatiles were evaporated and the residue dissolved in ether. The ether layer was washed with water then dried over Na2SO4, filtered and evaporated to give 8.7 g of crude product which was purified by chromatography on 300 g of silica gel eluting with CH2Cl2 to give 6.2 g of product as an oil. NMR (CDCl3) ppm (delta): 2.00-2.40 (m, 2H), 3.80 (s, 3H), 2.5 (t, 1H, J=4 Hz), 7.10-6.70 (m, 3H).

Workup

  1. customThe volatiles were evaporated
  2. dissolutionthe residue dissolved in ether
  3. washThe ether layer was washed with water
  4. dry with materialthen dried over Na2SO4
  5. filtrationfiltered
  6. customevaporated
  7. customto give 8.7 g of crude product which
  8. customwas purified by chromatography on 300 g of silica gel eluting with CH2Cl2

Sources & evidence

ORD record
ord-12eca53ae4b84a6fa20480de0c74d0d5
Source dataset
uspto-grants-1991_08
Patent number
US05039672

Reaction notes

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