Hydrochloric Acid → 3,4-dihydro-4-(2-hydroxy-2-phenylethyl)-2,2-dimethyl-6-nitro-2H-1,4-benzoxazine

HRID 37107Notes

Reaction equation

HRID 37107 reaction equation
[CH3:1][C:2]1([CH3:25])[C:7](=O)[N:6]([CH2:9][C:10]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)=[O:11])[C:5]2[CH:18]=[C:19]([N+:22]([O-:24])=[O:23])[CH:20]=[CH:21][C:4]=2[O:3]1.B.CO.Cl>O1CCCC1>[OH:11][CH:10]([C:12]1[CH:13]=[CH:14][CH:15]=[CH:16][CH:17]=1)[CH2:9][N:6]1[C:5]2[CH:18]=[C:19]([N+:22]([O-:24])=[O:23])[CH:20]=[CH:21][C:4]=2[O:3][C:2]([CH3:25])([CH3:1])[CH2:7]1

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 887MethanolHCID 6331BoraneHCID 107358923,4-dihydro-2,2-dimethyl-6-nitro-3-oxo-4-phenacyl-2H-1,4-benzoxazine

Product 1

HCID 106877203,4-dihydro-4-(2-hydroxy-2-phenylethyl)-2,2-dimethyl-6-nitro-2H-1,4-benzoxazineYield 115.4%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
70 °C

Procedure

In an argon gas stream, 1.5 g of 3,4-dihydro-2,2-dimethyl-6-nitro-3-oxo-4-phenacyl-2H-1,4-benzoxazine was added to 30 ml of a 1.0 M solution of borane in tetrahydrofuran at 0°-10° C. The above solution was stirred at 70° C. for 1 hour, at the end of which time 5.6 ml of methanol was gradually added. After stirring at 70° C. for 15 minutes, 5.6 ml of concentrated hydrochloric acid was added and the mixture was further stirred at 70° C. for 1 hour. The solvent was then distilled off and the residue was diluted with 30 ml of water, made alkaline with potassium carbonate, and extracted with ethyl acetate. The extract was dried over anhydrous magnesium sulfate and the solvent was distilled off. The residue was purified by silica gel column chromatography (eluent: ethyl acetate-n-hexane) to give 1.67 g of 3,4-dihydro-4-(2-hydroxy-2-phenylethyl)-2,2-dimethyl-6-nitro-2H- 1,4-benzoxazine as oil.

Workup

  1. additionwas gradually added
  2. stirringthe mixture was further stirred at 70° C. for 1 hour
  3. distillationThe solvent was then distilled off
  4. additionthe residue was diluted with 30 ml of water
  5. extractionextracted with ethyl acetate
  6. dry with materialThe extract was dried over anhydrous magnesium sulfate
  7. distillationthe solvent was distilled off
  8. customThe residue was purified by silica gel column chromatography (eluent: ethyl acetate-n-hexane)

Sources & evidence

ORD record
ord-2897d63c137948458c08aedaa03d0415
Source dataset
uspto-grants-1995_05
Patent number
US05420126

Reaction notes

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