BOC-SER(TBU)-OH

White to off-white crystals

l-Isobutyl-2, 3, 4, 9-tetrahydro- lH-pyrido[3, 4-]indole (457 mg, 2.00 mmol), l-ethyl-3- (3-dimethylaminopropyl)carbodiimide-HCl (EDC-HC1) (383 mg, 2.00 mmol), 4- dimethylaminopyridine (DMAP) (24 mg, 0.20 mmol), hydroxybenzotriazole (HOBT) (102 mg, 0.66 mmol), Step 1: To a solution of 0-benzyl-N-(tert-butoxycarbonyl)-L-homoserine (5 g, 16.2 mmol) in propan-2-ol (50 mL) was added dropwise thionyl chloride (11.7 mL, 161 mmol). The reaction was allowed to stir at 70C for 3 hours, then at room temperature for 16 hours. The reaction mixture was concentrated in vacuo, and the crude residue obtained was dissolved in THF. To the resulting solution was added DIEA (5.34 mL, 32.3 mmol) followed by methylchloroformate. The reaction was allowed to stir at room temperature for 3 hours, then a saturated aqueous H4C1 solution was added, and the resulting solution was extracted with dichloromethane. The combined organic layers were dried, filtered and concentrated in vacuo. The crude residue obtained was purified using flash chromatography on silica gel (dichloromethane: 100%) to provide the product. LC/MS: [(M+l)]+ = 310.6.Boc-Hse(OBn)-Phe tert-butyl amide (7). N-Boc-Hse(OBn)-OH (1.1796 g, 3.81mmol) was dissolved in dichloromethane (40 mL) and set to stir at 0 C. HOBt(0.7592 g, 4.96 mmol) was added to the reaction mixture, followed by EDCI(0.9510 g, 4.96 mmol) and phenylalanine tert-butylamide (1.2678 g, 5.75 mmol).The mixture was stirred at 0 C for 30 min, then for 6 h at room temperature. Thesolvent was removed in vacuo, and the residue was dissolved in ethyl acetate(25 mL) and washed with 1 N HCl (10 mL) and sat. NaHCO3 (10 mL). Theorganic phase was dried over sodium sulfate, filtered, and concentrated invacuo to afford a crude product that was purified by columnchromatography (SiO2, acetone/dichloromethane gradient, 1:9 to 2:3) to give 7as a white solid (1.9274 g, 98%). Mp: 48-51 C. [alpha]D25 -24.6 (c 1.02, MeOH). IR(neat): 3305, 3064, 3030, 2973, 2930, 2867, 1762, 1644, 1496, 1454, 1391, 1364, 1247, 1225, 1162, 1100, 1029, 912, 863, 738, 697, 607, 519, 494 cm-1. 1H NMR (500 MHz, CDCl3) delta 7.40 - 7.29 (m, 5H), 7.29 - 7.14 (m, 5H), 6.82 (d, J = 7.0 Hz, NH), 5.96 (s, NH), 5.83 (s, NH), 4.55 (dd, J = 13.0, 6.4 Hz, 1H), 4.46 (s, 2H), 4.16 (dd, J = 11.5, 5.6 Hz, 1H), 3.56 (d, J = 4.1 Hz, 2H), 3.19 (dd, J = 13.3, 4.5 Hz, 1H), 2.88 (dd, J =13.7, 7.3 Hz, 1H), 2.11 - 1.96 (m, 2H), 1.38 (s, 9H), 1.23 (s, 9H). 13C NMR (126MHz, CDCl3) delta 171.4, 169.4, 156.0, 137.8, 136.8, 129.5, 128.8, 128.6, 128.0, 127.8, 127.1, 80.2, 73.5, 68.3, 55.0, 54.4, 51.5, 38.1, 31.5, 28.6, 28.4. HRMS calcd. forC29H42N3O5 [M+H]+ 512.3119, found 512.3078.

Molecular Weight:309.36
XLogP3:2.3
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:5
Rotatable Bond Count:9
Exact Mass:309.15762283
Monoisotopic Mass:309.15762283
Topological Polar Surface Area:84.9
Heavy Atom Count:22
Complexity:358
Defined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes