تفاعل #2439925

معادلة التفاعل

p-fluorphenylboronic acid

3-bromo-5-hydroxymethyl-pyridine

Na2CO3

→

3-(p-fluorophenyl)-5-hydroxymethyl-pyridine

المردود 84.4%

المذيبات

toluene

ظروف التفاعل

المعالجة

1. 1
   أخرىthe biphasic reaction mixture
2. 2
   درجة الحرارةwas cooled
3. 3
   أخرىthe organic layer was collected
4. 4
   غسيلwashed with saturated NaCl
5. 5
   غسيلThe aqueous layer was washed with EtOAc
6. 6
   أخرىthe combined organic layers were dried on Na2SO4
7. 7
   أخرىThe drying agent was removed by filtration
8. 8
   أخرىthe solvent was evaporated in vacuo
9. 9
   أخرىto give a dark oil which
10. 10
    أخرىwas purified by flash chromatography on silica gel (eluent: CH2Cl2/MeOH/NH4OH, 95/4.5/0.5)

الإجراء التجريبي

To a solution of 3-bromo-5-hydroxymethyl-pyridine (3.3 g, 17.5 mmol) in toluene (35 ml) was added Pd(PPh3)4 (0.6 g, 0.52 mmol), an aqueous solution of Na2CO3 (17.5 ml of a 2M solution) and p-fluorphenylboronic acid (2.65 g, 19 mmol, dissolved in 8.5 ml EtOH). The mixture was heated at 80-90° C. for 1 hr and vigorously stirred. After the reaction was completed, the biphasic reaction mixture was cooled, the organic layer was collected and washed with saturated NaCl. The aqueous layer was washed with EtOAc and the combined organic layers were dried on Na2SO4. The drying agent was removed by filtration and the solvent was evaporated in vacuo to give a dark oil which was purified by flash chromatography on silica gel (eluent: CH2Cl2/MeOH/NH4OH, 95/4.5/0.5) and yielded 3-(p-fluorophenyl)-5-hydroxymethyl-pyridine (3.0 g, 84%). The product was converted into its monohydrochloride salt; the residue was dissolved in Et2O and treated with 16.5 eq of ethanolic HCl. The product 3-(p-fluorophenyl)-5-hydroxymethyl-pyridinium hydrochloride Q4-OH.HCl precipitated as a white solid which was collected by filtration and subsequent drying.

المصدر