Cyclohexanol → 3-Cyclohexyloxycarbonyl-imidazolidin-2-on-1-carbonyl chloride

Beteiligte Stoffe

Reaktionsschritte

Triethylamine (5.8 parts by weight) was added dropwise to a mixture of imidazolidin-2-on-1-carbonyl chloride (7.4 parts by weight), tetrahydrofurane (50 parts by volume) and cyclohexanol (5.5 parts by weight) while stirring, and cooling with ice, the mixture was then slowly stirred overnight at room temperature and subsequently boiled for 1 hour under reflux, and the triethylamine hydrochloride was filtered off hot. The filtrate was completely evaporated in vacuo, the residue was triturated with cyclohexane and the solid product was filtered off and dried 3 days in a desiccator. Yield: 5.0 parts by weight. This substance (5.0 parts by weight was then suspended in tetrahydrofurane, triethylamine (5.2 parts by volume) was added, the mixture was boiled under reflux and a solution of trimethylchlorosilane (3.8 parts by weight) in tetrahydrofurane (10 parts by volume) was at the same time added dropwise. Thereafter the mixture was boiled overnight under reflux and insoluble matter was then filtered off hot. A solution of phosgene (2.6 parts by weight) in tetrahydrofurane (10 parts by volume) was slowly added to the filtrate at room temperature and the mixture was left to stand well sealed at room temperature for 24 hours. A precipitate which was present (largely triethylamine hydrochloride) was then filtered off and the filtrate was completely evaporated in vacuo. The cyrstalline residue was dried in a desiccator. The substance has a broad absorption between 1680 and 1820 cm-1 in the carbonyl region of the IR-spectrum (Nujol). It was reacted, in this form, with ampicillin.

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