Benzylamine → HCID 12040685, compound

Temperature

70 °C

Tri-O-acetyl D-erythro-4-pentulosonic acid methyl ester 6 (15.2 g) was dissolved in methanol (85 ml) and acetic acid (3.1 g) and benzylamine (5.4 g) added. Sodium cyanoborohydride (3.1 g) was then added and the mixture kept at room temperature for 24 hours to reduce the imine to an amine 3. Sodium bicarbonate (6 g) and water 20 ml was added and the mixture heated for 4 hours at 70° C. to effect cyclization to the lactam 7. The mixture was concentrated to a syrup and partitioned between ethyl acetate (300 ml) and cold saturated sodium chloride (100 ml). The ethyl acetate layer was recovered, dried (sodium sulfate) and concentrated to a syrup. The syrup was dissolved in methanol (200 ml) to which was added potassium carbonate 20 g and water 2 ml. The resulting mixture was stirred at room temperature for 14 hours, filtered, the filtrate concentrated and the resulting syrup dissolved in methanol (400 ml). Concentrated HCl (4.1 ml) was added. A white solid was formed. This was removed by filtration and the filtrate concentrated to dryness. Methanol was added again and the solution again concentrated. This was repeated one more time to give the crude N-benzyl pyrrolidone which can be converted to the pyrrolidine to reduction.

1. concentrationThe mixture was concentrated to a syrup
2. custompartitioned between ethyl acetate (300 ml) and cold saturated sodium chloride (100 ml)
3. customThe ethyl acetate layer was recovered
4. dry with materialdried (sodium sulfate)
5. concentrationconcentrated to a syrup
6. dissolutionThe syrup was dissolved in methanol (200 ml) to which
7. additionwas added potassium carbonate 20 g and water 2 ml
8. filtrationfiltered
9. concentrationthe filtrate concentrated
10. dissolutionthe resulting syrup dissolved in methanol (400 ml)
11. additionConcentrated HCl (4.1 ml) was added
12. customA white solid was formed
13. customThis was removed by filtration
14. concentrationthe filtrate concentrated to dryness
15. additionMethanol was added again
16. concentrationthe solution again concentrated

ORD record

ord-ea9f8ff74ab64729960c280041da3fae

Source dataset

uspto-grants-2003_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06518437B1