반응 #65242

반응 방정식

1,2-dibromo-4,4-dimethylcyclopentene

4-fluorophenylboronic acid

ethanol

Na2CO3

→

1-(2-bromocyclopenten-1-yl)-4-fluorobenzene

수율 24.1%

용매

toluene

반응 조건

후처리

1. 1
   온도at reflux overnight
2. 2
   농축concentrated in vacuo
3. 3
   workup.DISSOLUTIONThe residue was dissolved in ethyl acetate
4. 4
   세척washed with water
5. 5
   건조dried (Na2SO4)
6. 6
   기타Purification by silica gel chromatography (MPLC) with hexane

실험 절차

Under nitrogen, 1.3 g (5.1 mmol) of 1,2-dibromo-4,4-dimethylcyclopentene (Step 8) was reacted with 600 mg (4.3 mmol) of 4-fluorophenylboronic acid (Lancaster) in 23 mL of toluene, 15 mL of of ethanol, and 10 mL of 2M Na2CO3 in the presence of 250 mg (5 mol %) of Pd(PPh3)4. The reaction was vigorously stirred at reflux overnight and concentrated in vacuo. The residue was dissolved in ethyl acetate and washed with water, dried (Na2SO4), and reconcentrated. Purification by silica gel chromatography (MPLC) with hexane gave 250 mg of 1-(2-bromocyclopenten-1-yl)-4-fluorobenzene (38 in Synthetic Scheme X when R1 and R2 =CH3, R5 =F, and R3, R4, R6 and R7 =H) as a pale yellow oil which was reacted with 200 mg (1.2 mmol) of 4-methylthiophenylboronic acid (Example 1, Step 1) in 5.2 mL of toluene, 3.4 mL of ethanol, and 2.2 mL of 2H Na2CO3 in the presence of 40 mg (5 mol %) of Pd(PPh3)4. The reaction was vigorously stirred at reflux for 6 hours and concentrated in vacuo. The residue was dissolved in ethyl acetate and washed with water, dried (Na2SO4), and reconcentrated. Purification by silica gel chromatography (MPLC) with hexane gave 120 mg of 1-[2-(4-fluorophenyl)-4,4-dimethylcyclopenten-1-]-4-(methylthio)benzene (41 in Synthetic Scheme X when R1 and R2 =CH3, RS=F, R10 =SCH3, and R3, R4, R6, R7, R8, R9, R11, and R12 =H) as an oil: NMR CDCl3) δ1.20 (s, 6H0, 2.42 (s, 3H), 2.63 (s, 4H), 6.90 (t, J=8 Hz, 2H), 7.00-7.18 (m, 4H), 7.30-7.60 (m, 2H).

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