반응 #344050

반응 방정식

rac-6-acetyloxy-2-ethynyl-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran

3-bromobenzothiophene

triphenylphosphine

triethylamine

→

title compound

rac-6-Acetyloxy-2-[(benzo[b]thiophen-3-yl)ethynyl]-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran

용매

dimethylformamide

반응 조건

후처리

1. 1
   기타degased by a stream of argon for 15 minutes
2. 2
   workup.ADDITIONPalladium acetate, 30 mg, was then added
3. 3
   기타The reaction mixture was partitioned between saturated sodium bicarbonate solution and toluene
4. 4
   세척The organic phase was washed with water
5. 5
   기타dried
6. 6
   기타evaporated
7. 7
   기타The residue was chromatographed over 50 g of silica gel
8. 8
   세척for elution
9. 9
   기타The combined clean fractions were crystallized from hexane

실험 절차

A mixture of 0.544 g of rac-6-acetyloxy-2-ethynyl-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran, 0.64 g of 3-bromobenzothiophene, 90 mg of triphenylphosphine, 20 mg of cuprous iodide, 2 ml of triethylamine and 40 ml of dimethylformamide was stirred and degased by a stream of argon for 15 minutes. Palladium acetate, 30 mg, was then added and the mixture was heated at 95° C. for 5 hours. The reaction mixture was partitioned between saturated sodium bicarbonate solution and toluene. The organic phase was washed with water, dried and evaporated. The residue was chromatographed over 50 g of silica gel using toluene for elution. The combined clean fractions were crystallized from hexane to give the title compound with m.p. 96°-99°.

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