Hydrochloric Acid → (3S,4R,5S,6R)-3-Amino-6-(hydroxymethyl)tetrahydro-2H-pyran-2,4,5-triol hydrochloride

Temperature

40 °C

To 12.0 g of N-benzyl-mannosamine of example 2A was added a suspension of 10% Pd/C (0.5 g) in 20 ml water. The pH of the reaction mixture was adjusted to 4-4.5 with 10% HCl solution. The reaction mixture was stirred for 6 hours at 40° C. under H2 pressure (2.5 bar). The pH was then adjusted to 3 with 10% HCl solution. The reaction mixture was kept unstirred overnight so that the catalyst could settle down (the catalyst remains in the reactor). The catalyst was filtered off and washed with a small amount of methanol:water (2:1). The methanol was removed in vacuo and replaced by 15 mL isopropanol. The isopropanol was distilled off and the same procedure was repeated again. To the reaction mixture, 30 ml iPrOH was added and the product crystallized overnight at 4° C. The crystals were filtered and washed with 5-8 mL isopropanol. The wet product was dried at room temperature, to give 8.4 g of D-mannosamine hydrochloride.

1. waitThe reaction mixture was kept unstirred overnight so that the catalyst
2. filtrationThe catalyst was filtered off
3. washwashed with a small amount of methanol:water (2:1)
4. customThe methanol was removed in vacuo
5. distillationThe isopropanol was distilled off
6. additionTo the reaction mixture, 30 ml iPrOH was added
7. customthe product crystallized overnight at 4° C
8. filtrationThe crystals were filtered
9. washwashed with 5-8 mL isopropanol
10. customThe wet product was dried at room temperature

ORD record

ord-92762c8b831545bea3b462439790cf3a

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09187513B2