Ammonia → 2,6-Dichlorobenzoxazole

HRID 986676Notes

Reaction equation

HRID 986676 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][C:3]=1[OH:8].NC(N)=O.N.[Cl:14]Cl.Cl.P(Cl)(Cl)(Cl)(Cl)Cl.[Cl:23][C:24]1(O)C=CC=CC1Cl>>[Cl:23][C:24]1[O:8][C:3]2[CH:4]=[C:5]([Cl:14])[CH:6]=[CH:7][C:2]=2[N:1]=1

Participants

8

Reactant 7

HCID 222AmmoniaHCID 313Hydrochloric AcidHCID 1176UreaHCID 58012-AminophenolHCID 24526ChlorineHCID 24819Phosphorus pentachlorideHCID 22630186HCID 22630186, compound

Product 1

HCID 771752,6-DichlorobenzoxazoleYield 61%

Procedure

109 g (1 mole) of 2-aminophenol and 63 g (1.05 mole) of urea are suspended in 350 ml of o-dichlorophenol and the suspension is heated to 150° to 160° C. under nitrogen for 3 hours, ammonia escaping. About 100 ml of the solvent are distilled off by a slight lowering of the pressure and subsequently 300 ml of fresh o-dichlobenzene are added. At an interior temperature of 110° C. 78 g (1.1 mole) of chlorine are then passed in within 1 to 2 hours, hydrogen chloride escaping. The raw mixture is reacted with phosphorus pentachloride and worked up analogously to Example 8. 115 g (61% of theory) of 2,6-dichlorobenzoxazole are obtained. GC purity: 96.8%.

Workup

  1. temperaturethe suspension is heated to 150° to 160° C. under nitrogen for 3 hours
  2. distillationAbout 100 ml of the solvent are distilled off by
  3. additionare added
  4. customAt an interior temperature of 110° C

Sources & evidence

ORD record
ord-6f6d1415312a455689fcaeb743985490
Source dataset
uspto-grants-1987_12
Patent number
US04714766

Reaction notes

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