Tributylphosphine → HCID 178470442, compound

Participants

Reaction Steps

A solution of Bu3P (3.90 iL) in dioxane (20 mL) is added to a stirred solution of ethyl 2-diazo-3-[2-fluoro-5-(4-morpholinylmethyl)phenyl]-3-oxopropanoate (Preparation 7, 3.16 g) in dry dioxane (56 mL). The mixture is stirred at room temperature for 30 min then gently refluxed for 1.5 h. The reaction is cooled and concentrated. The crude product is purified by column chromatography (CH2Cl2/MeOH, 99/1; CH2Cl2/MeOH, 98/2; CH2Cl2/MeOH, 95/5) to yield 0.200 g (4.5%) of the desired product as an off-white solid. Additional material can be obtained by heating the acyclic intermediate which was isolated in the chromatography at 130° C. in diglyme (32 mL) for 3.5 h. The resulting mixture is concentrated. The crude product is purified by column chromatography (CH2Cl2/MeOH, 99/1; CH2Cl2/MeOH, 98/2; CH2Cl2/MeOH, 95/5) to yield 0.531 g (30% %) of the desired product as a white solid to give an overall yield of 0.731 g (35%). Physical characteristics are as follows: m.p. 195-197° C. (dec); 1H NMR (DMSO-d6) δ 14.0, 8.01, 7.83, 7.67, 4.30, 3.60, 2.38, 1.30; MS (ESI-) for C16H19N3O4 m/z 316.1 (M—H)−.

Provenance & Evidence