Thionyl Chloride → 2,6-Dichloro-4-(4,5-dihydro-2-oxazolyl)phenol

HRID 1723350Notes

Reaction equation

HRID 1723350 reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]([CH:11]=[C:12]([Cl:15])[C:13]=1[OH:14])[C:5]([NH:7][CH2:8][CH2:9][OH:10])=O.S(Cl)(Cl)=O>>[Cl:1][C:2]1[CH:3]=[C:4]([C:5]2[O:10][CH2:9][CH2:8][N:7]=2)[CH:11]=[C:12]([Cl:15])[C:13]=1[OH:14]

Participants

3

Reactant 2

HCID 24386Thionyl ChlorideHCID 145517143,5-dichloro-4-hydroxy-N-(2-hydroxyethyl)benzamide

Product 1

HCID 1356214662,6-Dichloro-4-(4,5-dihydro-2-oxazolyl)phenolYield 99.3%

Procedure

3,5-Dichloro-4-hydroxy-N-(2-hydroxyethyl)benzamide (400 gm, 1.61 moles) was ground and sifted through a No. 20 mesh screen prior to use. To a stirred suspension of the above in 2.8 L isopropyl acetate was added thionyl chloride (285 gm, 2.41 moles) in a steady stream. An exotherm to 45°-50° C. developed and the gray suspension appeared lighter after a short time. After stirring 2.5 hr, the suspension was cooled to room temperature and filtered. The cake was rinsed with isopropyl acetate and dried in a vacuum oven at room temperature overnight. There was obtained 371 gm (86% yield) of 2,6-dichloro-4-(4,5-dihydro-2-oxazolyl)phenol in the form of its hydrochloride salt, m.p. 189°-191° C., acceptable for use in the next step. The purified free base had the m.p. 195° C. (decompn.).

Workup

  1. filtrationsifted through a No
  2. additionTo a stirred suspension of the above in 2.8 L isopropyl acetate
  3. customto 45°-50° C.
  4. filtrationfiltered
  5. washThe cake was rinsed with isopropyl acetate
  6. customdried in a vacuum oven at room temperature overnight

Sources & evidence

ORD record
ord-5c64e434eae744ea86331b9d241cc6b6
Source dataset
uspto-grants-1989_08
Patent number
US04861791

Reaction notes

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