Hexamethylphosphoramide → ethyl (S)-10-(2,6-dimethyl-4-pyridinyl)-8,9-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylate

HRID 1904596Notes

Reaction equation

HRID 1904596 reaction equation
Br[C:2]1[C:3]([F:23])=[C:4]([F:22])[C:5]2[C:15](=[O:16])[C:14]([C:17]([O:19][CH2:20][CH3:21])=[O:18])=[CH:13][N:7]3[C@@H:8]([CH3:12])[CH2:9][O:10][C:11]=1[C:6]=23.[CH3:24][C:25]1[CH:30]=[C:29]([Sn](C)(C)C)[CH:28]=[C:27]([CH3:35])[N:26]=1.CN(C)P(N(C)C)(N(C)C)=O>O1CCOCC1.Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[CH3:24][C:25]1[CH:30]=[C:29]([C:2]2[C:3]([F:23])=[C:4]([F:22])[C:5]3[C:15](=[O:16])[C:14]([C:17]([O:19][CH2:20][CH3:21])=[O:18])=[CH:13][N:7]4[C@@H:8]([CH3:12])[CH2:9][O:10][C:11]=2[C:6]=34)[CH:28]=[C:27]([CH3:35])[N:26]=1

Participants

6

Reactant 3

HCID 12679HexamethylphosphoramideHCID 129132682,6-Dimethyl-4-(trimethyl-stannyl)pyridineHCID 14501357ethyl (S)-10-bromo-8,9-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylate

Product 1

HCID 14501359ethyl (S)-10-(2,6-dimethyl-4-pyridinyl)-8,9-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylateYield 16.6%

Reagents, catalysts & solvents 2

HCID 178418476HCID 178418476, compoundCatalystHCID 312751,4-DioxaneSolvent

Procedure

To a mixture of 14.08 g ethyl (S)-10-bromo-8,9-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylate, 10.91 g 2,6-dimethyl-4-trimethylstannylpyridine and 6.3 ml hexamethylphosphoramide in 200 ml dioxane under nitrogen was added 1.27 g dichlorobis(triphenylphosphine)palladium. The reaction mixture was heated at reflux for 24 hrs. Most of the solvent was then removed in vacuo and the residue was extracted with ethyl acetate and water, and then with chloroform. The organic extracts were combined and concentrated. The residue was chromatographed on silica gel using as eluant chloroform and chloroform containing increasing amounts of methanol (1-3%). There was thereby obtained 2.5 g pure ethyl (S)-10-(2,6-dimethyl-4-pyridinyl)-8,9-difluoro-3-methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylate, light yellow solid, m.p. 295°-297° C., [α]D25 =-34.4° (1% in chloroform).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureat reflux for 24 hrs
  3. customMost of the solvent was then removed in vacuo
  4. extractionthe residue was extracted with ethyl acetate and water
  5. concentrationconcentrated
  6. customThe residue was chromatographed on silica gel using as eluant chloroform and chloroform containing
  7. temperatureincreasing amounts of methanol (1-3%)

Sources & evidence

ORD record
ord-24acc5de9c2447b7baebe7bbafb78bbf
Source dataset
uspto-grants-1989_06
Patent number
US04839355

Reaction notes

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