TCI Practical Example: Esterification Using N,N-DMF Di-tert-Butyl Acetal

We are proud to present the tert-butyl esterification of N-acetyl-L-phenylalanine using N,N-DMF di-tert-butyl acetal.

Used Chemicals

• N-Acetyl-L-phenylalanine [A1541]
• N,N-DMF Di-tert-butyl Acetal [for Esterification] [D1303]

Procedure

Ａ solution of N-acetyl-L-phenylalanine (1.0 g, 4.78 mmol) in N,N-DMF di-tert-butyl acetal (6.9 mL, 28.7 mmol, 6.0 eq.) was stirred at 60 °C for overnight. The solvent was removed under reduced pressure and the residue was purified by silica gel column chromatography (ethyl acetate:hexane = 1:1) to give tert-butyl N-acetyl-L-phenylalaninate as a colorless oil (1.20 g, 94% yield).

Experimenter’s Comments

The reaction mixture was monitored by UPLC.

Analytical Data

tert-Butyl N-Acetyl-L-phenylalaninate

¹H NMR (400 MHz, CDCl₃); δ 7.28–7.19 (m, 3H), 7.13-7.11 (m, 2H), 5.92 (brd, 1H, J = 7.6 Hz), 4.76–4.71 (m, 1H), 3.07 (d, 2H, J = 6.0 Hz), 1.96 (s, 3H), 1.38 (s, 9H).

Lead Reference

• Design and synthesis of novel macrocyclic 2-amino-6-arylpyrimidine Hsp90 inhibitors
  • A. Suda, H. Koyano, T. Hayase, K. Hada, K. Kawasaki, S. Komiyama, K. Hasegawa, T. A. Fukami, S. Sato, T. Miura, N. Ono, T. Yamazaki, R. Saitoh, N. Shimma, Y. Shiratori, T. Tsukuda, Bioorg. Med. Chem. Lett. 2012, 22, 1136.