Pyridine → UK-157147

HRID 1416170Notes

Reaction equation

HRID 1416170 reaction equation
[Si]([O:8][C:9]1[CH:10]=[C:11]([S:15]([C:18]2[CH:31]=[CH:30][C:21]3[O:22][C:23]([CH3:29])([CH3:28])[C@@:24]4([CH3:27])[O:26][C@H:25]4[C:20]=3[CH:19]=2)(=[O:17])=[O:16])[CH:12]=[CH:13][CH:14]=1)(C(C)(C)C)(C)C.[CH3:32][N:33]1[C:38](=[O:39])[CH:37]=[CH:36][C:35]([OH:40])=[N:34]1.N1C=CC=CC=1>C(O)C.CO.ClCCl>[CH3:32][N:33]1[C:38](=[O:39])[CH:37]=[CH:36][C:35]([O:40][C@H:25]2[C@@:24]([OH:26])([CH3:27])[C:23]([CH3:29])([CH3:28])[O:22][C:21]3[CH:30]=[CH:31][C:18]([S:15]([C:11]4[CH:12]=[CH:13][CH:14]=[C:9]([OH:8])[CH:10]=4)(=[O:17])=[O:16])=[CH:19][C:20]2=3)=[N:34]1

Participants

6

Reactant 3

HCID 1049PyridineHCID 24741391HCID 24741391, compoundHCID 178481946HCID 178481946, compound

Product 1

HCID 9869402UK-157147Yield 48.7%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 21226129Dichloromethane methanolSolvent

Procedure

(3S,4S)-6-(3-tert-Butyldimethylsilyloxyphenyl)sulphonyl-3,4-dihydro-3,4-epoxy-2,2,3-trimethyl-2H-benzo[b]pyran (2.0 g) (see Preparation 15) and 2,3-dihydro-2-methyl-3-oxo-6-hydroxypyridazine (1.5 g) (see J.Org.Chem, 1971, 36, 3372) were suspended in ethanol (30 ml), pyridine (0.31 g) was added and the mixture was heated under reflux (a calcium chloride drying tube was attached to the flask) for 100 hours. After cooling the reaction was filtered and the filtrate was evaporated to yield a solid which was dissolved in 0.5% methanol/dichloromethane and filtered again. The filtrate was again evaporated and the residue was chromatographed on silica eluting with a solvent gradient of 0.5:99.5 to 3.75:96.25 methanol: dichloromethane to yield (3S ,4R)-3,4-dihydro-4-(2,3-dihydro-2-methyl-3-oxo-pyridazin-6-yl)oxy-3-hydroxy-6-(3-hydroxyphenyl)sulphonyl-2,2,3-trimethyl-2H-benzo[b]pyran (1.0 g) as a white solid. Found: C,53.20; H,4.79; N,5.22. C23H24N2O7S, 0.75 CH2Cl2 requires C,53.00; H,4.79; N,5.10%.

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux (a calcium chloride drying tube
  3. customfor 100 hours
  4. temperatureAfter cooling the reaction
  5. filtrationwas filtered
  6. customthe filtrate was evaporated
  7. customto yield a solid which
  8. filtrationfiltered again
  9. customThe filtrate was again evaporated
  10. customthe residue was chromatographed on silica eluting with a solvent gradient of 0.5:99.5 to 3.75:96.25 methanol

Sources & evidence

ORD record
ord-76bd9be31b5047a59671d75aef49b2ba
Source dataset
uspto-grants-1999_06
Patent number
US05912244

Reaction notes

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