H-TYR(TBU)-OTBU HCL

White to off-white powder

(S)-tert-butyl 2-amino-3 -(4-(tert-butoxy)phenyl)propanoate hydrochloride (23-1) (3.48g, 1O.55mmol) and 2-(2-methoxyethoxy)acetic acid (23-2) (1.698g, 12.66mmol) were suspended in 50 mL CH2C12. 2, 4, 6-tripropyl- 1, 3, 5, 2, 4, 6-trioxatriphosphinane 2, 4, 6-trioxide (T3P) solution (50% in EtOAc, 13.43mL, 21.lOmmol) was added followed by DIEA (2.76 mL, 15.82mmol) immediately afterwards. The mixture was stirred at room temperature for 2 hours. The mixture was then treated with TFA (8.07 mL, lO5mmol) and stirred overnight. The mixture was concentrated under high vacuum. The residue was chromatographed on silica eluted with 0- 70% hexane/EtOAc-EtOH(3 :1) to afford (2-(2-methoxyethoxy)acetyl)-L-tyrosine (C23) as an oil. The oil slowly solidified on stand for a week at room temperature to afford a semi-solid.LC-MS ESJIAPCI calc'd. for C, 4H, 9N06 [M + 1] 298.12, found 298.19. 'H NIVIR 400 IVIFIz, DMSO-d6: 12.74 (s, 1H), 9.19 (s, 1H), 7.65 (d, J = 9.37 Hz, 1H), 6.99 (d, J = 8.45 Hz, 2H), 6.66 (d, J = 8.62 Hz, 2H), 4.44 (m, 1H), 3.85 (m, 2H), 3.41-3.56 (m, 4H), 3.26 (s, 1H), 2.99 (dd, J = 5.15 Hz, 14.00 Hz, 1H), 2.86 (dd, J = 8.58 Hz, 13.91 Hz, 1H)General procedure: Tert-butyl 2-(imidazo[1, 2-a]quinoxalin-4-ylamino)acetate (6a): Glycine tert-butyl ester hydrochloride (0.824 g, 4.9 mmol), N, N-diisopropylethylamine (1.6 mL, 9.8 mmol) and 4-chloroimidazo[1, 2-a]quinoxaline 5 (0.5 g, 2.5 mmol) were dissolved in dimethyl-formamide (10 mL) in a microwave adapted vial and sealed.The reaction mixture was irradiated at 150 C for 30 min. The solvent was removed under reduced pressure. The crude mixture was dissolved in ethyl acetate (100 mL) and successively washed with saturated aqueous ammonium chloride, distilled water and finally brine. The organic phase was dried onsodium sulfate, filtered and concentrated under reduced pressure. The product was purified by flash chromatography eluted with cyclohexane/ethyl acetate 80/20 to 50/50. The compound is obtained asa beige solid (42% yield). C16H18N4O2. MW: 298.34 g/mol.

Molecular Weight:329.9
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:7
Exact Mass:329.1757714
Monoisotopic Mass:329.1757714
Topological Polar Surface Area:61.6
Heavy Atom Count:22
Complexity:333
Defined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:2
Compound Is Canonicalized:Yes