تفاعل #56995

معادلة التفاعل

alcohol

2-bromo-cyclopent-2-enol

Intermediate D3

2-bromo-cyclopent-2-enol

isobutyl magnesium bromide

→

Intermediate D4

2-isobutyl-cyclopent-2-enol

المذيبات

THF

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةthe mixture was heated
2. 2
   درجة الحرارةto reflux for 3 h. (
3. 3
   أخرىquenched with sat. NH4Cl solution
4. 4
   ترشيحThe mixture was filtered
5. 5
   أخرىpartitioned between brine and diethyl ether
6. 6
   أخرىThe organic layer was removed
7. 7
   تجفيفdried over Na2SO4
8. 8
   ترشيحfiltered
9. 9
   تركيزconcentrated under vacuum
10. 10
    أخرىThe oil was purified by chromatography on SiO2 with 20% EtOAc

الإجراء التجريبي

The alcohol (Intermediate D3, 16 mmol) in THF (30 mL) at 0° C. was treated with isobutyl magnesium bromide (40 mmol). The catalyst, 1,3-bis(diphenylphosphino)propane nickel (II) chloride (0.75 mmol) (NiCl2dppp) was added in one portion and the mixture was heated to reflux for 3 h. (see: Organ et al. J. Org. Chem. 1997, 62, 1523, incorporated herein by reference). The reaction mixture was cooled to rt and quenched with sat. NH4Cl solution. The mixture was filtered and partitioned between brine and diethyl ether. The organic layer was removed and dried over Na2SO4, filtered and concentrated under vacuum. The oil was purified by chromatography on SiO2 with 20% EtOAc:Hx to yield 2-isobutyl-cyclopent-2-enol (Intermediate D4). Use of 2-isobutyl-cyclopent-2-enol (Intermediate D4) in Method A produced 4-(2-isobutyl-cyclopent-2-enylmethyl)-1,3-dihydro-imidazole-2-thione (Compound 20).

المصدر