Hydrochloric Acid → 3-Methyl-4-methoxy-7-(2-thienoyl)benzofuran

HRID 1084856Notes

Reaction equation

HRID 1084856 reaction equation
[CH3:1][C:2]1[C:6]2[C:7]([O:18][CH3:19])=[CH:8][CH:9]=[C:10]([C:11]([C:13]3[S:14][CH:15]=[CH:16][CH:17]=3)=[O:12])[C:5]=2[O:4][C:3]=1C(O)=O.N1C2C(=CC=CC=2)C=CC=1.Cl>[Cu].C(Cl)(Cl)Cl>[CH3:1][C:2]1[C:6]2[C:7]([O:18][CH3:19])=[CH:8][CH:9]=[C:10]([C:11]([C:13]3[S:14][CH:15]=[CH:16][CH:17]=3)=[O:12])[C:5]=2[O:4][CH:3]=1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 7047QuinolineHCID 15124001HCID 15124001, compound

Product 1

HCID 151240023-Methyl-4-methoxy-7-(2-thienoyl)benzofuran

Reagents, catalysts & solvents 2

HCID 23978CopperCatalystHCID 6212ChloroformSolvent

Conditions

Temperature
210 °C

Procedure

An intimate mixture of compound 2 (3.50 g, 11.0 mmol), quinoline (7 mL), and copper powder (0.70 g, 11.0 mol) was carefully heated to 210° C. and maintained at that temperature until gas evolution ceased (about 10 minutes). The resulting mixture was cooled to 80° C. and poured into 1N HCl (120 mL). Chloroform (50 mL) was added and the mixture stirred for 5 minutes and filtered through a pad of celite. The pad was washed with an additional portion of chloroform (25 mL). The organic layer was separated and the aqueous layer extracted with additional portions of chloroform (2×50 mL). The combined organic extracts were dried (Na2SO4) and concentrated. The crude product was purified by preparative HPLC using 15% ethyl acetate in hexane as eluant to afford 3-methyl-4-methoxy-7-(2-thienoyl)benzofuran. mp 131°-134° C.; 1H NMR d 2.40 (3H, d, J=1 Hz), 4.02 (3H, s), 6.71 (1H, d, J=8 Hz), 7.17 (1H, m), 7.38 (1H, d, J=1 Hz), 7.70 (3H, m).

Workup

  1. temperaturemaintained at that temperature until gas evolution
  2. custom(about 10 minutes)
  3. temperatureThe resulting mixture was cooled to 80° C.
  4. filtrationfiltered through a pad of celite
  5. washThe pad was washed with an additional portion of chloroform (25 mL)
  6. customThe organic layer was separated
  7. extractionthe aqueous layer extracted with additional portions of chloroform (2×50 mL)
  8. dry with materialThe combined organic extracts were dried (Na2SO4)
  9. concentrationconcentrated
  10. customThe crude product was purified by preparative HPLC

Sources & evidence

ORD record
ord-8c63c992ecb94369ae82d45eac14a26a
Source dataset
uspto-grants-1991_04
Patent number
US05006549

Reaction notes

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