Benzyl Bromide → 7-bromo-1H,2H,3H-pyrido[2,3-b][1,4]oxazin-2-one

HRID 1271208Notes

Reaction equation

HRID 1271208 reaction equation
C([N:8]1[C:13](=[O:14])[CH2:12][O:11][C:10]2[N:15]=[CH:16][C:17]([Br:19])=[CH:18][C:9]1=2)C1C=CC=CC=1.C(=O)([O-])[O-].[Cs+].[Cs+].C(Br)C1C=CC=CC=1>CN(C=O)C>[Br:19][C:17]1[CH:16]=[N:15][C:10]2[O:11][CH2:12][C:13](=[O:14])[NH:8][C:9]=2[CH:18]=1

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 10796Cesium carbonateHCID 184521401-Benzyl-7-bromo-1H-pyrido[2,3-b][1,4]oxazin-2-one

Product 1

HCID 45901417-bromo-1H,2H,3H-pyrido[2,3-b][1,4]oxazin-2-one

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

In concentrated hydrochloric acid (8 mL) was stirred intermediate 65 (1.0 g, 3.43 mmol) which was then cooled to 0° C. This was then treated, in parts, with tin dust (0.92 g, 7.8 mmol) and then warmed to 80° C. for 1 hour. The mixture was cooled to room temperature and diluted with water (100 mL). The mixture was stirred to form a precipitate. The solid was collected by filtration, washed with water (10 mL), and dried at 65° C. for 3 hours under a vacuum to give the title compound. MS: M++1=230.9 Da. Intermediate 67: 1-Benzyl-7-bromo-1H-pyrido[2,3-b][1,4]oxazin-2-one. In DMF (30 mL) was stirred intermediate 66 (650 mg, 2.83 mmol) and cesium carbonate (3.9 g, 12 mmol). To this was added, dropwise, benzyl bromide (513 mg, 3.0 mmol) and the mixture was stirred overnight at room temperature. The mixture was filtered free of insolubles and the DMF was evaporated at reduced pressure to give a crude oil which was purified by MPLC (90 g silica gel column, 9:1 (methylene chloride/ethyl acetate). The appropriate fractions were combined and evaporated at reduced pressure to give the title compound. MS: M++1=321.0 Da.

Workup

  1. additionTo this was added
  2. filtrationThe mixture was filtered free of insolubles
  3. customthe DMF was evaporated at reduced pressure
  4. customto give a crude oil which
  5. customwas purified by MPLC (90 g silica gel column, 9:1 (methylene chloride/ethyl acetate)
  6. customevaporated at reduced pressure

Sources & evidence

ORD record
ord-b5b80a5ebce243cc83b738639e242889
Source dataset
uspto-grants-2007_04
Patent number
US07205295B2

Reaction notes

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