Hydrochloric Acid → 2-Carbomethoxy-3-hydroxy-tropane, hydrochloride

To a solution of the 2-carbomethoxy-3-tropanone obtained in example 4 (17 g, 85 mmol) in 750 ml methanol cooled to -35° C. was added sodium borohydride (17 g, 450 mmol) and the mixture was stirred for 4 hours. The cooled solution was quenched by slow addition of concentrated hydrochloric acid (40 ml) and the mixture was concentrated in vacuo. Water (400 ml) was added and the pH was adjusted to 3 by addition of concentrated hydrochloric acid. After having washed the water phase three times with diethyl ether pH was adjusted to 11 by addition of concentrated ammonium hydroxide and the water phase was extracted three times with methylene chloride. Concentration in vacuo yielded oil which was dissolved in ethanol and added concentrated hydrochloric acid followed by concentration in vacuo. Freeze drying of the residue yielded the title compound as an amorphous product.

1. customThe cooled solution was quenched by slow addition of concentrated hydrochloric acid (40 ml)
2. concentrationthe mixture was concentrated in vacuo
3. additionWater (400 ml) was added
4. additionthe pH was adjusted to 3 by addition of concentrated hydrochloric acid
5. washAfter having washed the water phase three times with diethyl ether
6. additionpH was adjusted to 11 by addition of concentrated ammonium hydroxide
7. extractionthe water phase was extracted three times with methylene chloride
8. concentrationConcentration in vacuo
9. customyielded oil which
10. concentrationfollowed by concentration in vacuo
11. customFreeze drying of the residue

ORD record

ord-d1ed47c5d3ef41b8acdcda1760ca2bf8

Source dataset

uspto-grants-1998_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05736556