Benzo(B)Thiophene → 2-(Dimethoxyacetyl)benzothiophene

HRID 653037Notes

Reaction equation

HRID 653037 reaction equation
[S:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[CH:3]=[CH:2]1.C([Li])CCC.[CH3:15][O:16][CH:17]([O:26][CH3:27])[C:18](N1CCOCC1)=[O:19]>C1COCC1>[CH3:15][O:16][CH:17]([O:26][CH3:27])[C:18]([C:2]1[S:1][C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=2[CH:3]=1)=[O:19]

Participants

5

Reactant 3

HCID 7221Benzo(B)ThiopheneHCID 21298597N-(dimethoxyacetyl)morpholineHCID 178418339Butyllithium

Product 1

HCID 142769322-(Dimethoxyacetyl)benzothiophene

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

A solution of benzothiophene (7.11 g., 0.053 mol) in 120 ml. dry THF was cooled to 0°. Butyl lithium (35.3 ml. of 1.5 M in hexane, 0.053 mol) was added dropwise, maintaining 0°-5°, and the mixture then warmed to ambient temperature for 1.25 hours, cooled to -75° C. and N-(dimethoxyacetyl)morpholine (10.0 g., 0.053 mol) in 50 ml. dry THF added dropwise maintaining -75° to -70°. The reaction was quenched by adding to 300 ml. saturated NH4Cl and 300 ml. ether. The organic layer was separated, washed with brine, dried over MgSO4 and stripped to an oil, 14 g., which was distilled to yield purified title product, 8.00 g.; bp 137°-139°/0.25 mm.; tlc Rf 0.23 (6:1 hexane:ethyl acetate), 0.47 (2:1 hexane:ethyl acetate); 1H-nmr 3.6 (s, 6H), 5.2 (s, 1H), 7.3-7.6 (m, 2H), 7.8-8.05 (m, 2H), 8.4 (s, 1H), tlc Rf 0.31 (4:1 hexane:ethyl acetate), 0.47 (2:1 hexane:ethyl acetate).

Workup

  1. temperaturemaintaining 0°-5°
  2. temperaturecooled to -75° C.
  3. temperaturemaintaining -75° to -70°
  4. customThe reaction was quenched
  5. additionby adding to 300 ml
  6. customThe organic layer was separated
  7. washwashed with brine
  8. dry with materialdried over MgSO4
  9. distillation, which was distilled
  10. customto yield
  11. custompurified title product, 8.00 g

Sources & evidence

ORD record
ord-26a42c8077904bfbbe19a4c385ae8af4
Source dataset
uspto-grants-1987_06
Patent number
US04675186

Reaction notes

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