3-Bromopyridine → 3-(Trimethylstannyl)pyridine

Temperature

-50 °C

To a reaction vessel equipped with a mechanically driven agitator, water-cooled condenser, addition funnel, thermometer, and nitrogen inlet was added a solution containing 17.1 g. (0.108 mole) of 3-bromopyridine in 150 cc. of anhydrous ether. The solution was cooled to -50° C. using a dry ice-acetone bath. By a dropwise addition, 40 cc. (0.108 mole) of n-butyllithium in n-hexane was added over 14 minutes. The resulting yellow-orange solution was stirred for an additional 60 minutes. A solution containing 17.9 g. (0.09 mole) of trimethyltin chloride in 150 cc. of anhydrous benzene was added over 40 minutes, followed by a 75 minute stirring period. The dark orange solution was warmed to room temperature and stirred 18 hours before being hydrolyzed with a saturated aqueous solution of ammonium chloride. The aqueous phase was separated from the organic phase and washed with 200 cc. of ether. The organic portions were combined, dried over a quantity of anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. A dark red liquid (16.2 g.) was isolated and distilled under reduced pressure (0.1-0.2 mm.). A clear, colorless liquid fraction boiling at 50°-60° C. was collected and redistilled (6.5 mm.). The fraction boiling at 100°-103° C. was collected and analyzed. The tin content was found to be 48.89%. The calculated tin content for trimethyl-3-pyridyltin is 49.07%. Gas chromatographic analysis indicated a purity of 98% and the refractive index was recorded as 1.5399 at 25° C. The nuclear magnetic resonance spectrum contained a singlet at 0.33 ppm. (CH3 -Sn, 9H's), a complex multiplet centered at 7.2 ppm. (β-pyridyl H, 1H), a doublet of triplets at 7.75 ppm. (γ-pyridyl H, 1H), a doublet of doublets at 8.52 ppm. (γ-pyridyl H on 6 carbon, 1H), and a doublet at 8.65 ppm. (γ-pyridyl H on 2 carbon, 1H), in agreement with the expected structure.

1. temperaturecooled
2. additioncondenser, addition funnel
3. additionthermometer, and nitrogen inlet was added a solution
4. additioncontaining 17.1 g
5. additionBy a dropwise addition, 40 cc
6. additionA solution containing 17.9 g
7. waitfollowed by a 75 minute
8. stirringstirring period
9. temperatureThe dark orange solution was warmed to room temperature
10. stirringstirred 18 hours
11. customThe aqueous phase was separated from the organic phase
12. washwashed with 200 cc
13. dry with materialdried over a quantity of anhydrous magnesium sulfate
14. filtrationfiltered
15. concentrationconcentrated under reduced pressure
16. customA dark red liquid (16.2 g.) was isolated
17. distillationdistilled under reduced pressure (0.1-0.2 mm.)
18. customA clear, colorless liquid fraction boiling at 50°-60° C. was collected
19. distillationredistilled (6.5 mm.)
20. customThe fraction boiling at 100°-103° C. was collected
21. customwas recorded as 1.5399 at 25° C

ORD record

ord-69a50c16db344277accedca045e894fc

Source dataset

uspto-grants-1982_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04316853