9-Borabicyclo(3.3.1)nonane → 1-BENZYL-1,2,3,6-TETRAHYDROPYRIDINE

Temperature

25 °C

A solution of 5.16 g (20 mmoles) of 1-benzyl-4-morpholino-1,2,3,6-tetrahydropyridine in 10 ml of tetrahydrofuran (THF) is added to 2.44 g (20 mmoles) of solid 9-BBN. A suspension results which becomes clear after stirring for 6 hours at 25° C. The THF is removed under reduced pressure (20 Torr) and 2 ml of methanol is added to the remaining solid. An exothermic reaction is initiated by gentle warming and results in a clear solution which is stirred. The stirring is stopped and the mixture is cooled slowly to crystallize the by-product, B-(morpholino)-9-BBN methanol complex. The solid is triturated with n-pentane (3×30 ml) and the combined pentane layers are washed successively with water (3×10 ml), 3N sodium hydroxide (3×6 ml) and water (2×10 ml). The pentane layer is evaporated. The residue is purified by distillation to give 2.90 g (85 percent yield based on 1-benzyl-4-morpholino-1,2,3,6-tetrahydropyridine) of 1 -benzyl-1,2,3,6-tetrahydropyridine, boiling point 98° C.-100° C. at 1 Torr.

1. customA suspension results which
2. customThe THF is removed under reduced pressure (20 Torr) and 2 ml of methanol
3. additionis added to the remaining solid
4. customAn exothermic reaction
5. temperatureby gentle warming
6. customresults in a clear solution which
7. stirringis stirred
8. temperaturethe mixture is cooled slowly
9. customto crystallize the by-product, B-(morpholino)-9-BBN methanol complex
10. customThe solid is triturated with n-pentane (3×30 ml)
11. washthe combined pentane layers are washed successively with water (3×10 ml), 3N sodium hydroxide (3×6 ml) and water (2×10 ml)
12. customThe pentane layer is evaporated
13. distillationThe residue is purified by distillation

ORD record

ord-495122625cf2420483a5d77d18d66c5e

Source dataset

uspto-grants-1990_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04895996