Pyridine → Ammonia

HRID 1416172Notes

Reaction equation

HRID 1416172 reaction equation
[Si]([O:8][C:9]1[CH:14]=[CH:13][C:12]([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:11][CH:10]=1)(C(C)(C)C)(C)C.[OH:32][C:33]1[C:42]2[C:37](=[CH:38][CH:39]=[CH:40][CH:41]=2)[C:36](=[O:43])[N:35]([CH3:44])[N:34]=1.N1C=CC=CC=1>O1CCOCC1>[NH3:34].[CH3:44][N:35]1[N:34]=[C:33]([O:32][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:12]4[CH:11]=[CH:10][C:9]([OH:8])=[CH:14][CH:13]=4)(=[O:17])=[O:16])=[CH:19][C:20]2=3)[C:42]2[C:37](=[CH:38][CH:39]=[CH:40][CH:41]=2)[C:36]1=[O:43]

Participants

6

Reactant 3

HCID 1049PyridineHCID 57308558HCID 57308558, compoundHCID 178481940HCID 178481940, compound

Product 2

HCID 222AmmoniaYield 35%HCID 57179313(3S,4R)-3,4-dihydro-4-(1,2-dihydro-2-methyl-1-oxophthalazin-4-yl)oxy-3-hydroxy-6-(4-hydroxyphenyl)sulphonyl-2,2,3-trimethyl-2H-benzo[b]pyranYield 14.9%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Procedure

A mixture of (3S,4S)-6-(4-tert-butyldimethylsilyloxyphenyl)sulphonyl-3,4-dihydro-3,4-epoxy-2,2,3-trimethyl-2H-benzo[b]pyran (0.71 g) (see Preparation 14), 1,2-dihydro-4-hydroxy-2-methyl-1-oxophthalazine (0.846 g) (see Preparation 21), pyridine (0.4 ml) and 1,4-dioxane (10 ml) was heated under reflux for 4 days. The solvent was removed under reduced pressure, the residue was dissolved in ethyl acetate and washed first with dilute aqueous citric acid solution and then with brine. The organic phase was dried (anhydrous magnesium sulphate), the solvent was removed and the crude product was chromatographed on silica eluting with a solvent gradient of 100:1:0.15 to 180:20:1 dichloromethane: methanol: 35% aqueous ammonia solution to yield (3S,4R)-3,4-dihydro-4-(1,2-dihydro-2-methyl-1-oxophthalazin-4-yl)oxy-3-hydroxy-6-(4-hydroxyphenyl)sulphonyl-2,2,3-trimethyl-2H-benzo[b]pyran (0.12 g) as a solid.

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 4 days
  3. customThe solvent was removed under reduced pressure
  4. dissolutionthe residue was dissolved in ethyl acetate
  5. washwashed first with dilute aqueous citric acid solution
  6. dry with materialThe organic phase was dried (anhydrous magnesium sulphate)
  7. customthe solvent was removed
  8. customthe crude product was chromatographed on silica eluting with a solvent gradient of 100:1:0.15 to 180:20:1 dichloromethane

Sources & evidence

ORD record
ord-75ce86a371ff45c2a13d90a3aa9f4203
Source dataset
uspto-grants-1999_06
Patent number
US05912244

Reaction notes

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