Methanol → Boc-Cha-OMe

HRID 486873Notes

Reaction equation

HRID 486873 reaction equation
[C:1]([O:5][C:6]([NH:8][C@H:9]([C:17]([OH:19])=[O:18])[CH2:10][CH:11]1[CH2:16][CH2:15][CH2:14][CH2:13][CH2:12]1)=[O:7])([CH3:4])([CH3:3])[CH3:2].[CH3:20]O>>[CH3:20][O:18][C:17](=[O:19])[C@H:9]([CH2:10][CH:11]1[CH2:16][CH2:15][CH2:14][CH2:13][CH2:12]1)[NH:8][C:6]([O:5][C:1]([CH3:4])([CH3:2])[CH3:3])=[O:7]

Participants

3

Reactant 2

HCID 887MethanolHCID 10588189(2S)-2-(((tert-butoxy)carbonyl)amino)-3-cyclohexylpropanoic acid

Product 1

HCID 7018789Boc-Cha-OMe

Conditions

Temperature
40 °C

Procedure

After 25.0 ml (19.8 wt %) of methanol was added to 100 g of oily N-t-butyloxycarbonyl-3-cyclohexyl-L-alanine at room temperature (about 25° C.), the mixture was heated to 40° C. while stirring. When the temperature of liquid reached 40° C., methanol was evaporated under reduced pressure. Oily N-t-butyloxycarbonyl-3-cyclohexyl-L-alanine methyl ester was again obtained. Crystals of N-t-butyloxycarbonyl-3-cyclohexyl-L-alanine methyl ester prepared in Example 1 (1.0 g) were added to the oil as seed crystals. Cooling was gradually continued to 15° C. while stirring. The precipitated crystals were immediately separated by centrifuging, and were then washed with 5 ml of previously cooled methanol. After the obtained crystals were air-dried, the crystals were further dried at 30° C. overnight under reduced pressure to give 84.3 g of N-t-butyloxycarbonyl-3-cyclohexyl-L-alanine methyl ester as crystals. The powder X-ray chart for the crystals formed in this way resembled that shown in FIG. 1 for the crystals of Example 1.

Workup

  1. customreached 40° C.
  2. custommethanol was evaporated under reduced pressure

Sources & evidence

ORD record
ord-89ff7d81ecb14966a2a29e8cf462103b
Source dataset
uspto-grants-1994_03
Patent number
US05292925

Reaction notes

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