Triethylamine → HCID 71741590, compound

Participants

Reaction Steps

3-Methyl-cyclobutane-1,1-dicarboxylic acid ethyl ester (V. Prelog et al., Helv. Chim. Acta 65 (1982), 2622-2644; 200 mg, 1.074 mmol) was suspended in acetone (20 ml) and stirred in an ice bath. Triethylamine (152 mg, 1.50 mmol) and isobutyl chloroformate (191 mg, 1.40 mmol) were added, the mixture was stirred at 0° C. for 30 min, then sodium azide (129 mg, 1.99 mmol) as solution in water (10 ml) was added, and stirring was continued for 15 min. Then diethyl ether (50 ml) was added, the phases were separated. The organic layer was washed with water, dried over sodium sulfate, filtered and added to refluxing toluene in a flask with distillation bridge. The toluene solution was refluxed for 4 h, the volatiles were evaporated in vacuo, the residue was dissolved in dioxane, 2 N hydrochloric acid was added in excess, and the mixture was stirred until the isocyanate was completely decomposed (approximately 20 min). The volatiles were evaporated and the obtained amino acid ester hydrochloride was used without further purification.

Provenance & Evidence