Borohydride → (R)-2-Amino-3-cyclohexylpropan-1-ol

HRID 47749

Reaction equation

HRID 47749 reaction equation
[NH2:1][C@H:2]([CH2:8][CH:9]1[CH2:14][CH2:13][CH2:12][CH2:11][CH2:10]1)[C:3](OCC)=[O:4].[BH4-].[Na+].[BH4-]>C(O)C>[NH2:1][C@H:2]([CH2:8][CH:9]1[CH2:14][CH2:13][CH2:12][CH2:11][CH2:10]1)[CH2:3][OH:4]

Participants

5

Reactant 3

HCID 28123BorohydrideHCID 4311764Sodium borohydrideHCID 86584436ethyl (2R)-2-amino-3-cyclohexylpropanoate

Product 1

HCID 40432407(R)-2-Amino-3-cyclohexylpropan-1-olYield 105.5%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

The process is performed as in Example 1, starting with 6.2 g of ethyl (2R)-2-amino-3-cyclohexylpropionate and 1.93 g of sodium borohydride in 120 cm3 of absolute ethanol at about 5° C. for 10 minutes. The medium is warmed to room temperature and stirred for a further 3 h 30 minutes. After cooling again to about 5° C. and addition of a further 40.94 g of borohydride, followed by stirring at a temperature in the region of 20° C. for 65 hours, the reaction medium is concentrated under reduced pressure (5 kPa) at a temperature in the region of 40° C. A solid is obtained, which is purified by chromatography under a pressure of argon (100 kPa) on a column of silica gel (particle size 40-63μ; 320 g), eluting with pure methanol. The fractions containing the expected product are collected. These fractions are combined and then concentrated under reduced pressure (5 kPa) at a temperature in the region of 40° C. 5.16 g of (2R)-2-amino-3-cyclohexyl-1-propanol are obtained in the form of a sticky white solid. (Rf=0.25 in methanol on a Merck 60F254R silica plate).

Workup

  1. temperatureAfter cooling again to about 5° C.
  2. stirringby stirring at a temperature in the region of 20° C. for 65 hours
  3. concentrationthe reaction medium is concentrated under reduced pressure (5 kPa) at a temperature in the region of 40° C
  4. customA solid is obtained
  5. customwhich is purified by chromatography under a pressure of argon (100 kPa) on a column of silica gel (particle size 40-63μ; 320 g)
  6. washeluting with pure methanol
  7. additionThe fractions containing the expected product
  8. customare collected
  9. concentrationconcentrated under reduced pressure (5 kPa) at a temperature in the region of 40° C

Sources & evidence

ORD record
ord-15ed5e09c0304ee0806312e42daad942
Source dataset
uspto-grants-2004_03
Patent number
US06699895B2

Linked notes

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