Tributyltin azide → 3-Tetrazolyl-2-(1,1-dimethylethoxy)methanamidopropionic acid

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Reaction Steps

17.5 g (82 mmol, 1 equiv.) of the compound of Example 39 (3-cyano-2-(1,1-dimethylethoxy)methanamido-propionic acid) was dissolved in 125 mL of THF and 40.5 g (129 mmol, 1.5 equiv.) tributyltin azide was added. The reaction mixture was brought to reflux and held there for 3 days. The reaction mixture was cooled and the volatiles removed in vacuo on the rotary evaporator. The residue was dissolved in 300 mL of 0.5 M NaOH and this aqueous solution was washed with ethyl acetate (4×100 mL). The aqueous layer was passed through a 125 mL bed of Dowex 50X8-400 ion exchange resin and the resin washed with four column volumes of 1:1 methanol:water. The volatiles were removed in vacuo on the rotary evaporator to yield 17.9 g of the title compound as a white solid (85% yield). 1H-NMR (CD3OD): 4.55 p.p.m (m, 1H); 3.40 p.p.m. (m, 2H); 1.40 p.p.m. (s, 9H). This material is suitable for use in solid-phase peptide synthesis.

Provenance & Evidence