1-Trifluoroacetyl-1,4,5,6-tetra-hydropyrazine-2-carboxylic acid tert-butylamide → (S)-1-(Trifluoroacetyl)piperazine-2-carboxylic acid tert-butylamide

HRID 1419518Notes

Reaction equation

HRID 1419518 reaction equation
[C:1]([NH:5][C:6]([C:8]1[N:9]([C:14](=[O:19])[C:15]([F:18])([F:17])[F:16])[CH2:10][CH2:11][NH:12][CH:13]=1)=[O:7])([CH3:4])([CH3:3])[CH3:2]>[B-](F)(F)(F)F.C1CC=CCCC=C1.C1CC=CCCC=C1.[Rh].C(OCC)(=O)C>[C:1]([NH:5][C:6]([C@@H:8]1[CH2:13][NH:12][CH2:11][CH2:10][N:9]1[C:14](=[O:19])[C:15]([F:18])([F:16])[F:17])=[O:7])([CH3:4])([CH3:2])[CH3:3]

Participants

4

Reactant 1

HCID 117479071-Trifluoroacetyl-1,4,5,6-tetra-hydropyrazine-2-carboxylic acid tert-butylamide

Product 1

HCID 54528768(S)-1-(Trifluoroacetyl)piperazine-2-carboxylic acid tert-butylamideYield 99.3%

Reagents, catalysts & solvents 2

HCID 5702662Rhodium(1+), bis((1,2,5,6-eta)-1,5-cyclooctadiene)-, tetrafluoroborate(1-) (1:1)CatalystHCID 8857Ethyl AcetateSolvent

Procedure

250 g (8.95 mmol) of 1-trifluoroacetyl-1,4,5,6-tetra-hydropyrazine-2-carboxylic acid tert-butylamide, 7.5 mg (18 μmol) of bis(1,5-cyclooctadiene)rhodium(I) tetrafluoroborate and 11.5 mg (21 μmol) of 1-[1(R)-(di-tert-butylphosphino)ethyl]-2(S)-(diphenylphosphino)ferrocene were placed in a 50 ml autoclave under argon (educt:catalyst=486). 20 ml of degassed ethyl acetate was added and hydrogenation was carried out for 18 hours at 90° C. under a hydrogen pressure of 13-10 bar. After distillation of the solvent, 2.50 g of the crude title compound was obtained in the form of a light yellow powder. After cleavage of the protecting groups, the enantioselectivity of the hydrogenation was determined by GC analysis, giving an ee of 47.2 percent. Other data concerning the title compound was:

Workup

  1. distillationAfter distillation of the solvent

Sources & evidence

ORD record
ord-c0b754a4d62749dabd5625c3a4a38434
Source dataset
uspto-grants-1999_03
Patent number
US05886181

Reaction notes

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