1-Hydroxy-2-naphthoic acid → 2-[(1-Hydroxy-naphthalene-2-carbonyl)-amino]-2-methyl-propionic acid methyl ester

Participants

Reaction Steps

To a solution of 4.70 g 1-hydroxy-2-naphthalene carboxylic acid in 40 ml abs. DMF under inert atmosphere 3.72 g 1-hydroxybenzotriazole, 8.89 g N,N′-diisopropyl carbodiimide and 7 ml of N,N-diisopropylethylamine were added at 0° C. After 30 minutes at 0° C. 4.22 g of methyl 2-aminoisobutyrate hydrochloride, followed by 5 ml of N,N-diisopropylethylamine were added. After 16 h at room temperature the reaction mixture was concentrated, the residue was taken up in ethyl acetate and washed with 2 M HCl and brine. The organic layer was dried over magnesium sulphate, concentrated and the resulting residue was crystallized from toluene to yield 4.18 g of 2-[(1-hydroxy-naphthalene-2-carbonyl)-amino]-2-methyl-propionic acid methyl ester.

Provenance & Evidence