Hydrochloric Acid → 8-Bromo-6-methyl-2,3-dihydro-benzo[1,4]oxazine-4-carboxylic acid benzyl ester

HRID 388275Notes

Reaction equation

HRID 388275 reaction equation
Cl[C:2]([O:4][CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=[O:3].[Br:12][C:13]1[C:22]2[O:21][CH2:20][CH2:19][NH:18][C:17]=2[CH:16]=[C:15]([CH3:23])[CH:14]=1.N1C=CC=CC=1.Cl>ClCCl>[CH2:5]([O:4][C:2]([N:18]1[C:17]2[CH:16]=[C:15]([CH3:23])[CH:14]=[C:13]([Br:12])[C:22]=2[O:21][CH2:20][CH2:19]1)=[O:3])[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 1049PyridineHCID 10387Benzyl chloroformateHCID 225572458-Bromo-6-methyl-3,4-dihydro-2h-1,4-benzoxazine

Product 1

HCID 207656818-Bromo-6-methyl-2,3-dihydro-benzo[1,4]oxazine-4-carboxylic acid benzyl esterYield 96%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

A solution of benzyl chloroformate (1.32 g, 0.008 mol) in dichloromethane (20 mL) was added dropwise under nitrogen to an ice-cold solution of 8-bromo-6-methyl-3,4-dihydro-2H-benzo[1,4]oxazine (1.78 g, 0.007 mol) and pyridine (1.06 g, 0.013 mol) in dichlormethane (40 mL). After 1 hour at ambient temperature, a 10% aqueous HCl solution was added. The layers were separated and the organic phase was washed with water (50 mL×2), dried (Na2SO4) and concentrated to give 8-bromo-6-methyl-2,3-dihydro-benzo[1,4]oxazine-4-carboxylic acid benzyl ester as a colorless oil (2.34 g, 96%) which was used in the step 2 without purification.

Workup

  1. customThe layers were separated
  2. washthe organic phase was washed with water (50 mL×2)
  3. dry with materialdried (Na2SO4)
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-832489a8bc1a4e7088ce3fc1810c46d3
Source dataset
uspto-grants-2013_02
Patent number
US08377931B2

Reaction notes

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