Fmoc-L-Aspartic acid-1-benzyl ester

White solid

Fmoc-Asp(OtBu)-OBn (1.604 g, 3.197 mmol) was dissolved in 15 ml of freshly distilled CH2Cl2. 15 ml HCOOH is added to the solution and the mixture is stirred overnight at rt, after which TLC showed full conversion of the starting material. The volatiles were removed under reduced pressure and the remnants of HCOOH were removed by co- evaporation with CH2Cl2, yielding Fmoc-Asp(OH)-OBn as a white solid (1.310 g, 2.94 mmol, 92percent). 1H NMR (400 MHZ, Chloroform-d) 8 11.15 (s, 1H), 7.80 (d, J= 7.5 Hz, 2H), 7.66 (d, J= 7.4 HZ, 2H), 7.44 (t, J= 7.4 Hz, 2H), 7.36 (d, J= 7.4 HZ, 7H), 6.16 (d, J= 8.5 HZ, 1H), 5.26 (s, 2H), 4.83 (dt, J= 8.6, 4.4 Hz, 1H), 4.50 (dd, J= 10.4, 7.4 HZ, 1H), 4.46 — 4.38 (m, 1H), 4.26 (t, J= 7.1 HZ, 1H), 3.18 (dd, J= 17.4, 4.6 Hz, 1H), 3.01 (dd, J= 17.4, 4.2 HZ, 1H) 130 NMR (101 MHZ, CDC13)8 175.36, 170.34, 156.04, 143.53, 143.39, 141.02, 134.84, 128.34, 128.20, 127.94, 127.51, 126.87, 124.90, 119.76, 67.44, 67.21, 50.18, 46.79, 36.12.In aame-driedask, under N2ow, General procedure: Peptides were synthesized on a CSBio CS336X peptide synthesizer following theFmoc-based solid phase peptide synthesis method. The loading capacity of resin is0.156 mmol and the scale of amino acid is 1 mmol. General procedure for Fmoc-solidphase peptide synthesis: firstly, the resin was swelled with DCM/DMF (1:1) for anhour and washed the resin with DMF and DCM five times. The resin was then treatedwith 20% piperidine in DMF and the removed Fmoc was monitored by a UV detectoruntil completion. Then, the resin was washed with DMF and DCM again. After this2.5 mL (0.4M HATU), 2.5 mL (0.8 DIPEA) and 2.5ml DMF was added to dissolvethe amino acid then the mixture was transferred to the reaction flask and kept onshaking for 45 mins. After 45 mins, the resin was washed with DMF and DCM fivetimes the Fmoc deprotection was performed by 20% piperidine until the UV detectorindicated the complete releasing of Fmoc. Then, subsequent coupling cycles withsequenced amino acids were carried out following the above process until the targetpeptide was obtained. After filtration and washing with DMF and DCM, the resin wasdried under vacuum for 2h. For HPLC and LC-MS analysis, a small amount ofpeptide on resin was treated with a cleavage cocktail reagent to release the peptide, the resin was removed by filtration and the TFA in the filtrate was removed byblowing with N2. Then the residue was treated with cold diethyl ether for 3 times toprecipitate the crude peptide as a white powder. The crude peptide was subject to theHPLC and LC-MS analysis.General procedure: Peptides were synthesized on a CSBio CS336X peptide synthesizer following theFmoc-based solid phase peptide synthesis method. The loading capacity of resin is0.156 mmol and the scale of amino acid is 1 mmol. General procedure for Fmoc-solidphase peptide synthesis: firstly, the resin was swelled with DCM/DMF (1:1) for anhour and washed the resin with DMF and DCM five times. The resin was then treatedwith 20% piperidine in DMF and the removed Fmoc was monitored by a UV detectoruntil completion. Then, the resin was washed with DMF and DCM again. After this2.5 mL (0.4M HATU), 2.5 mL (0.8 DIPEA) and 2.5ml DMF was added to dissolvethe amino acid then the mixture was transferred to the reaction flask and kept onshaking for 45 mins. After 45 mins, the resin was washed with DMF and DCM fivetimes the Fmoc deprotection was performed by 20% piperidine until the UV detectorindicated the complete releasing of Fmoc. Then, subsequent coupling cycles withsequenced amino acids were carried out following the above process until the targetpeptide was obtained. After filtration and washing with DMF and DCM, the resin wasdried under vacuum for 2h. For HPLC and LC-MS analysis, a small amount ofpeptide on resin was treated with a cleavage cocktail reagent to release the peptide, the resin was removed by filtration and the TFA in the filtrate was removed byblowing with N2. Then the residue was treated with cold diethyl ether for 3 times toprecipitate the crude peptide as a white powder. The crude peptide was subject to theHPLC and LC-MS analysis.

Molecular Weight:445.5
XLogP3:4
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:6
Rotatable Bond Count:10
Exact Mass:445.15253745
Monoisotopic Mass:445.15253745
Topological Polar Surface Area:102
Heavy Atom Count:33
Complexity:668
Defined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes