Реакция #65242

Уравнение реакции

1,2-dibromo-4,4-dimethylcyclopentene

4-fluorophenylboronic acid

ethanol

Na2CO3

→

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

Выход 24.1%

Растворители

toluene

Условия реакции

Обработка

1. 1
   Температураat reflux overnight
2. 2
   Концентрированиеconcentrated in vacuo
3. 3
   workup.DISSOLUTIONThe residue was dissolved in ethyl acetate
4. 4
   Промывкаwashed with water
5. 5
   Сушкаdried (Na2SO4)
6. 6
   ДругоеPurification by silica gel chromatography (MPLC) with hexane

Методика

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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