Hydrochloric Acid → 7-Acetyl-5-(benzyloxy)-1,3-benzoxazol-2(3H)-one

HRID 1867320Notes

Reaction equation

HRID 1867320 reaction equation
[C:1](Cl)(Cl)=[O:2].[NH2:5][C:6]1[C:7]([OH:23])=[C:8]([C:20](=[O:22])[CH3:21])[CH:9]=[C:10]([O:12][CH2:13][C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[CH:11]=1.[Cl-].[NH4+].Cl>C1(C)C=CC=CC=1.ClCCl.C(N(CC)CC)C>[C:20]([C:8]1[C:7]2[O:23][C:1](=[O:2])[NH:5][C:6]=2[CH:11]=[C:10]([O:12][CH2:13][C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[CH:9]=1)(=[O:22])[CH3:21]

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 6371Phosgene2×HCID 25517Ammonium ChlorideHCID 210728221-(3-Amino-5-(benzyloxy)-2-hydroxyphenyl)ethanone

Product 1

HCID 210728587-Acetyl-5-(benzyloxy)-1,3-benzoxazol-2(3H)-one

Reagents, catalysts & solvents 3

HCID 1140TolueneSolventHCID 6344DichloromethaneSolventHCID 8471TriethylamineSolvent2×

Procedure

51.1 mL (97.04 mmol) of a phosgene solution (20% by weight in toluene) are added at 0° C. to a solution of 22.7 g (88.22 mmol) of 1-(3-amino-5-benzyloxy-2-hydroxyphenyl)ethanone in toluene (200 mL). Then 30.7 mL (220.6 mmol) of triethylamine is added dropwise such that the temperature does not exceed 5° C. After 1 hour stirring at ambient temperature, a further 4.6 mL of phosgene solution and 12 mL of triethylamine are added at 0° C. The mixture is stirred for 1 hour at ambient temperature, diluted with dichloromethane and combined with saturated aqueous ammonium chloride solution (500 mL) and 2 N aqueous hydrochloric acid (10 mL). After the aqueous phase has been separated off it is exhaustively extracted with dichloromethane. The combined organic phases are washed with water and saturated aqueous sodium chloride solution, dried with sodium sulfate and evaporated down in vacuo, during which time a beige solid is precipitated. The precipitate is filtered off, washed with a little toluene, and dried at 50° C. in vacuo. Yield: 18.5 g (74%); Rf=0.19 (silica gel, toluene/acetone 95:10); ESI-MS: [M+H]+=284.

Workup

  1. customdoes not exceed 5° C
  2. stirringThe mixture is stirred for 1 hour at ambient temperature
  3. customAfter the aqueous phase has been separated off it
  4. extractionis exhaustively extracted with dichloromethane
  5. washThe combined organic phases are washed with water and saturated aqueous sodium chloride solution
  6. dry with materialdried with sodium sulfate
  7. customevaporated down in vacuo, during which time a beige solid
  8. customis precipitated
  9. filtrationThe precipitate is filtered off
  10. washwashed with a little toluene
  11. customdried at 50° C. in vacuo

Sources & evidence

ORD record
ord-6c736ffd407b44508d6e12834de5e710
Source dataset
uspto-grants-2009_12
Patent number
US07632834B2

Reaction notes

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