Hydrochloric Acid → 8-bromo-2,2-dimethyl-3,4-dihydro-2H-benzo[1,4]oxazine hydrochloride

HRID 1270100Notes

Reaction equation

HRID 1270100 reaction equation
[Br:1][C:2]1[C:11]2[O:10][C:9]([CH3:13])([CH3:12])[C:8](=O)[NH:7][C:6]=2[CH:5]=[CH:4][CH:3]=1.CSC.B.[ClH:19]>O1CCCC1>[ClH:19].[Br:1][C:2]1[C:11]2[O:10][C:9]([CH3:13])([CH3:12])[CH2:8][NH:7][C:6]=2[CH:5]=[CH:4][CH:3]=1

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 12423031(Dimethyl sulfide)trihydroboronHCID 218735118-Bromo-2,2-dimethyl-2H-1,4-benzoxazin-3(4H)-one

Product 1

HCID 184490998-bromo-2,2-dimethyl-3,4-dihydro-2H-benzo[1,4]oxazine hydrochlorideYield 92%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

8-Bromo-2,2-dimethyl-4H-benzo[1,4]oxazin-3-one from step 2 (768.30 mg, 3.0 mmol) was dissolved in dry tetrahydrofuran (THF) and the solution was heated to reflux. 0.3 ml of 10M borane dimethyl sulfide (BH3.DMS) in THF was added drop-wise to the reaction mix, and the reaction mix was kept heated under reflux for 1 hour. A solution of 10% ethanolic HCl was then added drop-wise to the reaction mix until a white precipitate appeared, after which refluxing was continued for 10 minutes. The reaction mix was cooled, and the precipitate was removed by filtration, washed with ether, and air dried to yield 770 mg of 8-bromo-2,2-dimethyl-3,4-dihydro-2H-benzo[1,4]oxazine hydrochloride (92%) as a white solid. MS: (M+H) 280.

Workup

  1. temperaturethe solution was heated to reflux
  2. additionmix
  3. additionthe reaction mix
  4. temperaturewas kept heated
  5. temperatureunder reflux for 1 hour
  6. additionmix until a white precipitate
  7. temperatureafter which refluxing
  8. additionThe reaction mix
  9. temperaturewas cooled
  10. customthe precipitate was removed by filtration
  11. washwashed with ether, and air
  12. customdried

Sources & evidence

ORD record
ord-608f292c004a4898b81cb57a51d220f7
Source dataset
uspto-grants-2007_04
Patent number
US07202241B2

Reaction notes

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