Hydrochloric Acid → (2-Hydroxy-5-ethylphenyl)(2-thienyl)methanone

HRID 66311Notes

Reaction equation

HRID 66311 reaction equation
[OH:1][C:2]1[CH:10]=[CH:9][C:8]([CH2:11][CH3:12])=[CH:7][C:3]=1[C:4]([OH:6])=O.S(Cl)(Cl)=O.OC1C=CC(CC)=CC=1C(Cl)=O.[Cl-].[Al+3].[Cl-].[Cl-].[S:33]1[CH:37]=[CH:36][CH:35]=[CH:34]1.Cl>C(=S)=S.N1C=CC=CC=1>[OH:1][C:2]1[CH:10]=[CH:9][C:8]([CH2:11][CH3:12])=[CH:7][C:3]=1[C:4]([C:34]1[S:33][CH:37]=[CH:36][CH:35]=1)=[O:6]

Participants

9

Reactant 6

HCID 313Hydrochloric AcidHCID 8030ThiopheneHCID 24386Thionyl ChlorideHCID 4389305-Ethyl-2-hydroxybenzoic acidHCID 6451240Aluminum(III) ChlorideHCID 138388205-Ethyl-2-hydroxybenzoyl chloride

Product 1

HCID 13838807(2-Hydroxy-5-ethylphenyl)(2-thienyl)methanoneYield 2.9%

Reagents, catalysts & solvents 2

HCID 1049PyridineSolventHCID 6348Carbon DisulfideSolvent2×

Procedure

2-Hydroxy-5-ethylbenzoic acid (16.6g, 0.1 mol) and thionyl chloride (12.44g, 0.105 mol) were mixed together with light petroleum (bp 40°-60° C.) (75 ml) and pyridine (0.1 ml) and refluxed for 6 hours. The resulting 2-hydroxy-5-ethylbenzoyl chloride was stirred in carbon disulphide (120 ml), cooled in ice and treated with aluminium chloride for 1 to 2 minutes. The temperature of the mixture rose from 2° C. to 15° C. The temperature was allowed to return to about 2° C. and thiophene (8.4g, 7.91 ml. 0.1 mol) in carbon disulphide (25 ml) was added at a rate such that the temperature of the mixture did not rise above about 3° C. The mixture was then stirred at room temperature overnight, stirred and refluxed for 31/2 hours, cooled, poured into ice and concentrated hydrochloric acid, and extracted with ether. The ether fraction was washed firstly with a saturated solution of sodium bicarbonate and secondly with a saturated solution of sodium chloride, was dried (over Na2SO4), filtered and evaporated to yield an oil which was distilled to give the pure title product (0.67g), bp 118°-122° C./0.07 mm, nD19 1.6280.

Workup

  1. temperaturerefluxed for 6 hours
  2. temperaturecooled in ice
  3. customrose from 2° C. to 15° C
  4. customto return to about 2° C.
  5. customdid not rise above about 3° C
  6. stirringstirred
  7. temperaturerefluxed for 31/2 hours
  8. temperaturecooled
  9. extractionextracted with ether
  10. washThe ether fraction was washed firstly with a saturated solution of sodium bicarbonate and secondly with a saturated solution of sodium chloride
  11. dry with materialwas dried (over Na2SO4)
  12. filtrationfiltered
  13. customevaporated
  14. customto yield an oil which
  15. distillationwas distilled

Sources & evidence

ORD record
ord-c2c31d898cef40969596bf62824dab01
Source dataset
uspto-grants-1978_12
Patent number
US04131682

Reaction notes

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