Water → HCID 57285323, compound

HRID 1420750Notes

Reaction equation

HRID 1420750 reaction equation
[CH3:1][N:2]1[C:7](=[O:8])[CH:6]=[CH:5][C:4]([O:9][C@H:10]2[C@@:15]([OH:17])([CH3:16])[C:14]([CH3:19])([CH3:18])[O:13][C:12]3[CH:20]=[CH:21][C:22]([S:24]([C:27]4[CH:32]=[CH:31][C:30]([O:33]C)=[C:29]([O:35]C)[CH:28]=4)(=[O:26])=[O:25])=[CH:23][C:11]2=3)=[N:3]1.O>ClCCl.B(Br)(Br)Br>[CH3:1][N:2]1[C:7](=[O:8])[CH:6]=[CH:5][C:4]([O:9][C@H:10]2[C@@:15]([OH:17])([CH3:16])[C:14]([CH3:19])([CH3:18])[O:13][C:12]3[CH:20]=[CH:21][C:22]([S:24]([C:27]4[CH:32]=[CH:31][C:30]([OH:33])=[C:29]([OH:35])[CH:28]=4)(=[O:26])=[O:25])=[CH:23][C:11]2=3)=[N:3]1

Participants

5

Reactant 2

HCID 962WaterHCID 57274384HCID 57274384, compound

Product 1

HCID 57285323HCID 57285323, compoundYield 69.8%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolvent3×HCID 25134Boron tribromideSolvent

Procedure

(3S,4R)-3,4-Dihydro-4-(2,3-dihydro-2-methyl-3-oxopyridazin-6-yl)oxy-6-(3,4-dimethoxyphenyl)sulphonyl-3-hydroxy-2,2,3-trimethyl-2H-benzo[b]pyran (0.50 g) (see Preparation 26) was dissolved in dichloromethane (12 ml) (under a nitrogen atmosphere) and boron tribromide (4 ml of a 1 M solution in dichloromethane) was added. The mixture was stirred at room temperature for one hour and a precipitate was formed. Water (20 ml) and dichloromethane (15 ml) were added, an insoluble gum formed and the solvents were decanted off. The gum was then chromatographed on silica using 1:9 methanol:dichloromethane as the eluent to yield (3S,4R)-3,4-dihydro-4-(2,3-dihydro-2-methyl-3-oxopyridazin-6-yl)oxy-6-(3,4-dihydroxyphenyl)sulphonyl-3-hydroxy-2,2,3-trimethyl-2H-benzo[b]pyran (0.33 g) as a white foam which was then triturated with diethyl ether and dried to give a white solid.

Workup

  1. additionwas added
  2. customa precipitate was formed
  3. customan insoluble gum formed
  4. customthe solvents were decanted off
  5. customThe gum was then chromatographed on silica using 1:9 methanol

Sources & evidence

ORD record
ord-acc4df06b0bf48c6941123d0ea348ba2
Source dataset
uspto-grants-2000_06
Patent number
US06071938

Reaction notes

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