Pyridine → HCID 57274384, compound

HRID 1416192Notes

Reaction equation

HRID 1416192 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([S:11]([C:14]2[CH:27]=[CH:26][C:17]3[O:18][C:19]([CH3:25])([CH3:24])[C@@:20]4([CH3:23])[O:22][C@H:21]4[C:16]=3[CH:15]=2)(=[O:13])=[O:12])[CH:6]=[CH:7][C:8]=1[O:9][CH3:10].[CH3:28][N:29]1[C:34](=[O:35])[CH:33]=[CH:32][C:31]([OH:36])=[N:30]1.N1C=CC=CC=1>O1CCOCC1>[CH3:28][N:29]1[C:34](=[O:35])[CH:33]=[CH:32][C:31]([O:36][C@H:21]2[C@@:20]([OH:22])([CH3:23])[C:19]([CH3:25])([CH3:24])[O:18][C:17]3[CH:26]=[CH:27][C:14]([S:11]([C:5]4[CH:6]=[CH:7][C:8]([O:9][CH3:10])=[C:3]([O:2][CH3:1])[CH:4]=4)(=[O:13])=[O:12])=[CH:15][C:16]2=3)=[N:30]1

Participants

5

Reactant 3

HCID 1049PyridineHCID 57066493HCID 57066493, compoundHCID 178481946HCID 178481946, compound

Product 1

HCID 57274384HCID 57274384, compoundYield 42.8%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

(3S,4S)-3,4-Dihydro-6-(3,4-dimethoxyphenyl)sulphonyl-3,4-epoxy-2,2,3-trimethyl-2H-benzo[b]pyran (3.0 g) (see Preparation 25) and 2,3-dihydro-2-methyl-3-oxo-6-hydroxypyridazine (2.0 g) (see J.Org.Chem, 1971, 36, 3372) were suspended in dry 1,4-dioxane (30 ml), pyridine (0.61 g) was added and the mixture heated under reflux (a calcium chloride drying tube was attached to the flask) for 2 days. The solvent was removed under reduced pressure, the residue stirred with 5% methanol/dichloromethane and filtered. The filtrate was evaporated and the crude product chromatographed on silica eluting with 2.5:97.5 methanol: dichloromethane as the eluent to yield (3S,4R)-3,4-dihydro-4-(2,3-dihydro-2-methyl-3-oxo-pyridazin-6-yl)oxy-6-(3,4-dimethoxyphenyl)sulphonyl-3-hydroxy-2,2,3-trimethyl-2H-benzo[b]pyran (1.7 g) as a yellow foam.

Workup

  1. temperaturethe mixture heated
  2. temperatureunder reflux (a calcium chloride drying tube
  3. customfor 2 days
  4. customThe solvent was removed under reduced pressure
  5. filtrationfiltered
  6. customThe filtrate was evaporated
  7. customthe crude product chromatographed on silica eluting with 2.5:97.5 methanol

Sources & evidence

ORD record
ord-465ee9131e9f4847b93e6aad5f7003fa
Source dataset
uspto-grants-1999_06
Patent number
US05912244

Reaction notes

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