Triethylamine → 3-oxo-1-cyclohexen-1-yl 2,3-dihydrospiro[4H-1-benzothiopyran-4,2'-[1,3]dioxolane]-6-carboxylate 1,1-dioxide

HRID 617698Notes

Reaction equation

HRID 617698 reaction equation
[O:1]1[CH2:5][CH2:4][O:3][C:2]21[C:10]1[CH:11]=[C:12]([C:15]([OH:17])=[O:16])[CH:13]=[CH:14][C:9]=1[S:8](=[O:19])(=[O:18])[CH2:7][CH2:6]2.C(Cl)(=O)C(Cl)=O.[C:26]1(=O)[CH2:31][CH2:30][CH2:29][C:28](=[O:32])[CH2:27]1.C(N(CC)CC)C>CN(C)C=O.C(Cl)Cl>[O:1]1[CH2:5][CH2:4][O:3][C:2]21[C:10]1[CH:11]=[C:12]([C:15]([O:17][C:26]3[CH2:31][CH2:30][CH2:29][C:28](=[O:32])[CH:27]=3)=[O:16])[CH:13]=[CH:14][C:9]=1[S:8](=[O:19])(=[O:18])[CH2:7][CH2:6]2

Participants

7

Reactant 4

HCID 8471TriethylamineHCID 104341,3-CyclohexanedioneHCID 65578Oxalyl chlorideHCID 675608462,3-dihydrospiro[4H-1-benzothiopyran-4,2'-[1,3]dioxolane]-6-carboxylic acid 1,1-dioxide

Product 1

HCID 218490223-oxo-1-cyclohexen-1-yl 2,3-dihydrospiro[4H-1-benzothiopyran-4,2'-[1,3]dioxolane]-6-carboxylate 1,1-dioxideYield 82.7%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideCatalystHCID 6344DichloromethaneSolvent

Conditions

Temperature
0 °C

Procedure

2.0 g (7.0 mmol) of the title compound of Step E, 1.2 mL (0.014 mol) of oxalyl chloride (purchase from Janssen), and 2 drops of N,N-dimethylformamide were added to 50 mL of methylene chloride. The mixture was refluxed under nitrogen for 2 h, and was then evaporated to dryness. 50 mL of methylene chloride was added to the residue and the resulting mixture was evaporated to dryness. Another 50 mL of methylene chloride was added to the residue, and the solution was cooled to about 0° C. 0.86 g (7.7 mmol) of 1,3-cyclohexanedione (purchased from Aldrich Chemical Company) was added followed by 2.7 mL (0.0196 mol) of triethylamine, and the mixture was stirred overnight while warming to room temperature. The mixture was evaporated to dryness, the residue was stirred in 100 mL of water and filtered. The crude product was washed with hexane to yield 2.19 g of the title compound of Step F as a solid melting at 185-186° C. 1H NMR (CDCl3): δ2.2 (m,2H), 2.5 (t,2H), 2.7 (t,4H), 3.7 (m,2H), 4.2 (m,2H), 4.3 (m,2H), 6.0 (s,1H), 8.0-8.25 (3H).

Workup

  1. temperatureThe mixture was refluxed under nitrogen for 2 h
  2. customwas then evaporated to dryness
  3. addition50 mL of methylene chloride was added to the residue
  4. customthe resulting mixture was evaporated to dryness
  5. additionAnother 50 mL of methylene chloride was added to the residue
  6. temperaturewhile warming to room temperature
  7. customThe mixture was evaporated to dryness
  8. stirringthe residue was stirred in 100 mL of water
  9. filtrationfiltered
  10. washThe crude product was washed with hexane

Sources & evidence

ORD record
ord-adb458926fd74e01affac2a5d17300b9
Source dataset
uspto-grants-1999_09
Patent number
US05952266

Reaction notes

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