Hydrochloric Acid → 6-Acetyl-2-ethoxycarbonyl-4-methyl-3,4-dihydro-2H-1,4-benzoxazine

HRID 1106469Notes

Reaction equation

HRID 1106469 reaction equation
[C:1](Cl)(=[O:3])[CH3:2].[Cl-].[Al+3].[Cl-].[Cl-].[CH2:9]([O:11][C:12]([CH:14]1[CH2:19][N:18]([CH3:20])[C:17]2[CH:21]=[CH:22][CH:23]=[CH:24][C:16]=2[O:15]1)=[O:13])[CH3:10].Cl>ClCCl>[C:1]([C:22]1[CH:23]=[CH:24][C:16]2[O:15][CH:14]([C:12]([O:11][CH2:9][CH3:10])=[O:13])[CH2:19][N:18]([CH3:20])[C:17]=2[CH:21]=1)(=[O:3])[CH3:2]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 6367Acetyl chlorideHCID 6451240Aluminum(III) ChlorideHCID 10608998ethyl 4-methyl-3,4-dihydro-2H-1,4-benzoxazine-2-carboxylate

Product 1

HCID 187883576-Acetyl-2-ethoxycarbonyl-4-methyl-3,4-dihydro-2H-1,4-benzoxazine

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

1.6 mmol (0.1 ml) of acetyl chloride and 4 mmol (545 mg) of aluminum chloride are added to a solution of 1.6 mmol (355 mg) of 2-ethoxycarbonyl-4-methyl-3,4-dihydro-2H-1,4-benzoxazine (described in J. Heterocyclic Chem., 1985, 22, 177) in 18 ml of dichloromethane at -10° C. The reaction mixture is stirred at room temperature for 1 hour before being hydrolysed by a cooled aqueous solution of 2 M hydrochloric acid. The mixture is extracted with dichloromethane and the organic phase is washed with a saturated solution of NaHCO3, dried over magnesium sulphate, concentrated and purified by chromatography on silica gel using a petroleum ether/ethyl acetate mixture (7/3) as eluant to yield the expected product.

Workup

  1. extractionThe mixture is extracted with dichloromethane
  2. washthe organic phase is washed with a saturated solution of NaHCO3
  3. dry with materialdried over magnesium sulphate
  4. concentrationconcentrated
  5. custompurified by chromatography on silica gel using a petroleum ether/ethyl acetate mixture (7/3) as eluant

Sources & evidence

ORD record
ord-6d6eea817f214c47b12be816da30a37a
Source dataset
uspto-grants-2000_05
Patent number
US06057317

Reaction notes

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