Triethylamine → Boc-Arg(NO2)-Gly-NH2

Participants

Reaction Steps

This process is adapted from R. L. Huguenin et al., Helv. Chim. Acta, 48, 1885 (1965). Boc-nitroarginine (7.12 g., 22.3 mmole), glycinamide hydrochloride (2.46 g., 22.3 mmole), triethylamine (3.0 ml., 22.3 mmole) and 1-hydroxybenzotriazole monohydrate (3.42 g., 22.3 mmole) were dissolved in a mixture of tetrahydrofuran (THF) (30 ml.), acetonitrile (30 ml.), and water (8 ml.). Dicyclohexylcarbodiimide (4.66 g., 22.6 mmole) in 10 ml. of 1:1 THF/acetonitrile was added dropwise during 10 min. The resulting mixture was stirred at room temperature for 17 hours, filtered, and the solid washed with 1:1 THF/acetonitrile. Most of the product was mixed with dicyclohexyl urea in the filtered solids. Crystallization from MeOH/ether gave pure Boc-Arg(NO2)-Gly-NH2, 5.95 g. (71% yield): mp 151°-153° C. (dec); [α]58924 +0.21, [α]46324 +3.00 (c, 1.4, MeOH).

Provenance & Evidence