Methyl 6-fluoro-2,3-dihydro-2'-oxo-spiro[4H-benzopyran-4,1'-cyclopentane]-3'-carboxylate → 6-fluoro-2,3-dihydro-2'-oxo-spiro[4H-benzopyran-4,1'-cyclopentane]

HRID 2248287Notes

Reaction equation

HRID 2248287 reaction equation
[F:1][C:2]1[CH:3]=[CH:4][C:5]2[O:20][CH2:19][CH2:18][C:8]3([CH2:12][CH2:11][CH:10](C(OC)=O)[C:9]3=[O:17])[C:6]=2[CH:7]=1>Cl>[F:1][C:2]1[CH:3]=[CH:4][C:5]2[O:20][CH2:19][CH2:18][C:8]3([CH2:12][CH2:11][CH2:10][C:9]3=[O:17])[C:6]=2[CH:7]=1

Participants

3

Reactant 1

HCID 19094455Methyl 6-fluoro-2,3-dihydro-2'-oxo-spiro[4H-benzopyran-4,1'-cyclopentane]-3'-carboxylate

Product 1

HCID 149865456-fluoro-2,3-dihydro-2'-oxo-spiro[4H-benzopyran-4,1'-cyclopentane]

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidSolvent2×

Procedure

A mixture of 10.6 g (0.038 mol) of Methyl 6-fluoro-2,3-dihydro-2'-oxo-Spiro[4H-benzopyran-4,1'-cyclopentane]-3'-carboxylate in 280 ml of 1N HCl containing 8 ml of concentrated HCl was heated at reflux for 3 hours. The reaction was cooled to room temperature and extracted twice with EtOAc. The combined extracts were dried over NaSO4 and filtered. The filtrate was evaporated in vacuo to a solid residue (5.7 g, 68%) which was recrystallized from petroleum ether: m.p. 49°-51° C. NMR (CDCl3) (delta) 1.7-2.7 (m, 8H, CH2), 4.0-4.5 (m, 2H, CH2), 6.4-6.9 (m, 3H, arom).

Workup

  1. temperaturewas heated
  2. temperatureat reflux for 3 hours
  3. extractionextracted twice with EtOAc
  4. dry with materialThe combined extracts were dried over NaSO4
  5. filtrationfiltered
  6. customThe filtrate was evaporated in vacuo to a solid residue (5.7 g, 68%) which
  7. customwas recrystallized from petroleum ether

Sources & evidence

ORD record
ord-6d2a43d2fb8b488f9f5420b7707d713d
Source dataset
uspto-grants-1991_08
Patent number
US05039672

Reaction notes

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