Triethylamine → Amino-2-ethyl-4-hydroxy-7-methyloctanoic acid isobutylamide

Temperature

-15 °C

22.9 mg of L-N-[(2R or S)-5-ethylsulfonyl-2-(1-naphthylmethyl)pentanoyl]norleucine was dissolved in 0.2 ml of dry DMF, and 6.23 mg of triethylamine and 16.9 mg of DPPA were added under stirring at -15° C. Then, 26.8 mg of (2RS,4S,5S)-5-amino-2-ethyl-4-hydroxy-7-methyloctanoic acid isobutylamide monohydrochloride was dissolved in 0.1 ml of dry DMF and neutralized with 8.79 mg of triethylamine. This dry DMF solution was added to the previous reaction solution, and the mixture was stirred at -10° C. for one hour and at 5° C. overnight. The reaction solution was diluted with 20 ml of ethyl acetate, and the ethyl acetate layer was washed with water and with a saturated sodium chloride aqueous solution and dried over anhydrous sodium sulfate. Then, the solvent was distilled off, and the residue thereby obtained was purified by silica gel column chromatography (chloroform/methanol=75/1) to obtain 18.2 mg of (2RS,4 S,5S)-5-(L-N-[(2R or S)-5-ethylsulfonyl-2-(1-naphthylmethyl)pentanoyl]norleucyl}amino-2-ethyl-4-hydroxy-7-methyloctanoic acid isobutylamide as colorless solid.

1. stirringthe mixture was stirred at -10° C. for one hour and at 5° C. overnight
2. washthe ethyl acetate layer was washed with water and with a saturated sodium chloride aqueous solution
3. dry with materialdried over anhydrous sodium sulfate
4. distillationThen, the solvent was distilled off
5. customthe residue thereby obtained
6. customwas purified by silica gel column chromatography (chloroform/methanol=75/1)

ORD record

ord-67c20cbad4d64365a3a0373e18b2091a

Source dataset

uspto-grants-1994_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05319082