Синтез та деякі перетворення алкіл N-(2-арил-3-нітро-1,1,1-трифторопропан-2-іл)карбаматів

• Дата: 2014
• Автори: Tkachuk, V. M., Melnichenko, N. V., Kovalchuk, K. V., Sukach, V. A., Vovk, M. V., Nenaidenko, V. G.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: National University of Pharmacy 2014
• Теми: 2; 2-trifluoroethylidecarbamates; N-(3-nitro-1; 1; 1-trifluoropropan-2-yl)carbamates; N-(3-amino-1; 4-trifluoromethylimidazolidin-2-ones; 3; 3-trifluoropropan-1; 2-diamines; UDC 547.495.1 547.412.12 547.415.1; 2-трифтороэтилиденкарбаматы; N-(3-нитро-1; 1-трифторопропан-2-ил)карбаматы; N-(3-амино-1; 4-трифторометилимидазолидин-2-оны; 3-трифторопропан-1; 2-диамины; УДК 547.495.1 547.412.12 547.415.1; 2-трифтороетиліденкарбамати; N-(3-нітро-1; 1-трифторопропан-2-іл)карбамати; N-(3-аміно-1; 4-трифторометилімідазолідин-2-они; 2-діаміни
• Онлайн доступ: https://ophcj.nuph.edu.ua/article/view/ophcj.14.818
• Назва журналу: Journal of Organic and Pharmaceutical Chemistry

The paper is devoted to preparation and study of the transformations of novel multifunctional fluorinated synthetic building blocks – alkyl N-(3-nitro-1,1,1-trifluoropropan-2-yl) carbamates. In order to obtain them in high yields the aza-Henry reaction of 2,2,2-trifluoroethylidencarbamates with nitromethane catalyzed by triethylamine has been proposed. The structure of the compounds obtained has been confirmed by spectral methods. Essential elements of the structure corroboration are 13C NMR spectra, in which a signal of the newly formed stereogenic carbon atom is found as a quartet at 63 ppm. It has been shown that the interaction of sodium borohydride with alkyl N-(3-nitro-1,1,1-trifluoropropan-2-yl)carbamates in the presence of the equimolar amount of NiCl2.6H2O leads to selective reduction of the nitro group and formation of the corresponding alkyl N-(3-aminopropan-2-yl)carbamates. The presence of amino group in their structure considerably affects the chemical shifts of diastereotopic methylene protons. Their signals in the 1H NMR spectra are upfield (about 2 ppm difference in comparison with nitro derivatives). Alkyl N-(3-aminopropan-2-yl)carbamates in refluxing toluene in the presence of DBU were easily transformed into 4-trifluorometylimidazolidyn-2-ones by intramolecular cyclization. In its turn, tert-butyl N-(3-aminopropan-2-yl)carbamates when treating with hydrogen chloride in dioxane readily gave 3,3,3-trifluoropropan-1,2-diamines through Boc protecting group cleavage.