* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
(R)-3-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-4-(tert-butoxy)-4-oxobutanoic acid[ No CAS ]
[ 1375014-04-2 ]
Yield
Reaction Conditions
Operation in experiment
83%
With diisopropyl-carbodiimide; In dichloromethane; at 20℃;Cooling with ice;
General procedure: To an ice cooled stirred solution of 8-aminoquinoline (1 or 3, 2.53 mmol) and orthogonally protected amino acid (2.79 mmol) in anhydrous CH2Cl2 (5 mL), DIC (2.79 mmol) was added. The reaction mixture was allowed to attain room temperature and stirring continued for another 4 h. The solvent was removed under reduced pressure to obtain the crude product. Purification by column chromatography on silica gel (100-200 mesh) using 0.6% CH3OH in CH2Cl2 produced 61-68.
Stage #1: (R)-3-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-4-(tert-butoxy)-4-oxobutanoic acid With HATU In N,N-dimethyl-formamide at 0℃; for 0.05h;
Stage #2: methylamine With N-ethyl-N,N-diisopropylamine In water; N,N-dimethyl-formamide at 20℃; for 1h;
tert-bulvi N2-(((’9H-fluoren-9-yl,)rnethoxy,)carbonvl,.)-i-rnethvl-D-asparaginate
1007491 Prepared using General Procedures 7: To (R)-3-((((9H-fluoren-9- yl)methoxy)carbonyl)amino)-4-(tert-butoxy)-4-oxobutanoic acid (205.7 mg, 0.5 mrnol) in DMF (5 mL) at 0°C was added HATU (380 mg, 1.0 mmol). After stirring for 3 mm, DIEA (277 iL, 1.5 mmol) and methylamine (40 wt % in water, 116 jiL, 1.5 mrnol) were added. The reaction mixture was stirred at room temperature for 1 h. The reaction mixture was added to water (75 mL) and the precipitate was filtered and dried to give 201 rng (95%) of tert-butyl N2-(((9H-fluoren-9-yl)methoxy)carbonyl)-A-methy1-D- asparaginate as a colorless semi-solid. LCMS-ESI (ni’z) calculated for C24H28N205:424.2; found 425.2 [M+H],tR= 3.22 mm (Method 16).