Hydrochloric Acid → 6-Chloro-2h-1,3-benzoxazine-2,4(3h)-dione

HRID 19443

Reaction equation

HRID 19443 reaction equation
[Cl:1][C:2]1[CH:3]=[CH:4][C:5]([OH:11])=[C:6]([CH:10]=1)[C:7]([NH2:9])=[O:8].N1C=CC=CC=1.Cl[C:19](OCC)=[O:20].Cl>O.C(#N)C>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[O:11][C:19](=[O:20])[NH:9][C:7](=[O:8])[C:6]=2[CH:10]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 1049PyridineHCID 10928Ethyl chloroformateHCID 3480945-Chloro-2-hydroxybenzamide

Product 1

HCID 903596-Chloro-2h-1,3-benzoxazine-2,4(3h)-dioneYield 85.3%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6342AcetonitrileSolvent

Conditions

Temperature
95 °C

Procedure

A solution of 10 g of 5-chloro-2-hydroxybenzamide (58.0 mmol), pyridine (22 ml) and acetonitrile (25 ml) was stirred in an ice bath. Ethyl chloroformate (6.1 ml, 0.0638 mol) was added dropwise. The pink solution was stirred for 30 minutes at <10° C. The ice bath was replaced with an oil bath. The reaction mixture was heated to 95° C. and the volatiles were distilled off (43 ml). The reaction was cooled to room temperature, causing a white solid to form. The mixture was poured into water (100 ml) and acidified with concentrated aqueous hydrochloric acid. The resulting solid was filtered and recrystallized in hot ethanol to give 9.77 g of 6-chloro-2H-1,3-benzoxazine-2,4(3H)-dione.

Workup

  1. distillationthe volatiles were distilled off (43 ml)
  2. temperatureThe reaction was cooled to room temperature
  3. customto form
  4. filtrationThe resulting solid was filtered
  5. customrecrystallized in hot ethanol

Sources & evidence

ORD record
ord-d1b5b65db5a349c791c13059ce7ef66b
Source dataset
uspto-grants-2010_06
Patent number
US07744910B2

Linked notes

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