Hydrochloric Acid → 4-(4,4-Dimethyl-2,5-dioxoimidazolidin-1-yl)-2-pentafluorosulfanylbenzonitrile

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Reaction Conditions

Reaction Steps

To prepare compound 51.1, the procedure may be according to process “A”. 505 mg of amine 51.9 and 227.1 mg of triphosgene were dissolved in 15 ml of dry tetrahydrofuran. At 0° C., over 30 minutes, 0.864 ml of triethylamine in 2.5 ml of tetrahydrofuran was added dropwise and then the mixture was stirred at 5° C. for a further 10 minutes. 404.7 mg of the hydrochloride of tert-butyl 2-amino-2-methylpropionate were added, and the mixture was allowed to warm to room temperature and stirred at room temperature for a further 2 h. The reaction mixture was admixed with 2.5 ml of concentrated hydrochloric acid and stirred at room temperature for a further 2 h. For workup, the mixture was admixed with water and ethyl acetate, and the organic phase was removed, washed with saturated sodium chloride solution, dried over magnesium sulfate, filtered and concentrated under reduced pressure. The chromatographic purification was effected according to method [RP1]. The product-containing fractions were concentrated under reduced pressure, the residue was extracted by repeated shaking with dichloromethane, and the organic phase was dried over magnesium sulfate and concentrated under reduced pressure. 51.1 was obtained in 41% yield. 1H NMR: 8.85, s, 1H, 8.4, s, 1H, 8.3, d, 1H, 8.02, d, 1H, 1.4, s, 6H.

Provenance & Evidence