Borane;tetrahydrofuran → 7-bromo-1H,2H,3H-pyrido[2,3-b][1,4]oxazine

HRID 1660847Notes

Reaction equation

HRID 1660847 reaction equation
B.O1CCCC1.[Br:7][C:8]1[CH:17]=[C:16]2[C:11]([O:12][CH2:13][C:14](=O)[NH:15]2)=[N:10][CH:9]=1>O1CCCC1>[Br:7][C:8]1[CH:17]=[C:16]2[C:11]([O:12][CH2:13][CH2:14][NH:15]2)=[N:10][CH:9]=1

Participants

4

Reactant 2

HCID 2723981Borane;tetrahydrofuranHCID 45901417-bromo-1H,2H,3H-pyrido[2,3-b][1,4]oxazin-2-one

Product 1

HCID 667890617-bromo-1H,2H,3H-pyrido[2,3-b][1,4]oxazineYield 69.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
100 °C

Procedure

Borane-tetrahydrofuran complex (1 M in tetrahydrofuran, 32 mL, 32 mmol) was added dropwise at 0° C. to a solution of 7-bromo-1H-4-oxa-1,5-diaza-naphthalen-2-one (1.45 g, 6.33 mmol) in tetrahydrofuran (240 mL). The ice bath was removed and the solution heated at reflux over 3 h, then volatile material was removed by distillation. The residue was taken up in 37% aq. hydrochloric acid solution and the reaction mixture, heated at 100° C. for 75 min, basified to pH 10 with 30% aq. sodium hydroxide solution, and extracted three times with dichloromethane. The combined organic layers were dried (Na2SO4) and evaporated to afford 7-bromo-2,3-dihydro-1H-4-oxa-1,5-diaza-naphthalene (944 mg, 69%). White solid, MS (ISP)=215.1 (M+H)+.

Workup

  1. customThe ice bath was removed
  2. temperaturethe solution heated
  3. temperatureat reflux over 3 h
  4. customvolatile material was removed by distillation
  5. extractionextracted three times with dichloromethane
  6. dry with materialThe combined organic layers were dried (Na2SO4)
  7. customevaporated

Sources & evidence

ORD record
ord-2222b82aaa7648eba48c49bb5886a2ff
Source dataset
uspto-grants-2011_10
Patent number
US08030308B2

Reaction notes

Loading…