- A method for the production of primary amines
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The invention relates to the field of chemical industry and particularly relates to a method for preparing primary amine by using the raw materials including halogenated hydrocarbon (or hydrocarbon alcohol sulfonate) and ammonia water (or formamide). The method comprises the following three steps: (1) imidization: 3,4-diarylfuran-2,5-diketone (I) reacts with ammonia (or formamide) and the like to obtain 3,4-diaryl-1H-pyrrole-2,5-diketone (II); (2) N-hydrocarbylation: 3,4-diaryl-1H-pyrrole-2,5-diketone (II) generates an N-hydrocarbylation reaction with halogenated hydrocarbon (or hydrocarbon alcohol sulfonate) in the presence of alkali to obtain N-hydrocarbyl-3,4-diaryl-1H-pyrrole-2,5-diketone (III); and (3) hydrolysis: N-hydrocarbyl-3,4-diaryl-1H-pyrrole-2,5-diketone (III) is subjected to alkali hydrolysis to obtain primary amine and the generated 2,3-diaryl maleate is subjected to acid treatment and automatic ring closing to form 3,4-diaryl furan-2,5-diketone (I) which is subjected to imidization and directly applied to the N-hydrocarbylation reaction. The method provided by the invention has the characteristics that the 3,4-diaryl furan-2,5-diketone can be circularly used at a high recovery rate, the molar ratio of the raw materials is low, and the yield of the product primary amine is high.
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Paragraph 0237; 0277
(2016/10/09)
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- Reaction of InCl3 with various reducing agents: InCl 3-NaBH4-mediated reduction of aromatic and aliphatic nitriles to primary amines
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While alternative methods of preparing dichloroindium hydride (HInCl 2) via the in situ reduction of InCl3 using lithium amino borohydride (LAB) were explored, generation of HInCl2 from the reduction of InCl3 by sodium borohydride (NaBH4) was also re-evaluated for comparison. The reductive capability of the InCl 3/NaBH4 system was found to be highly dependent on the solvent used. Investigation by 11B NMR spectroscopic analyses indicated that the reaction of InCl3 with NaBH4 in THF generates HInCl2 along with borane-tetrahydrofuran (BH 3?THF) in situ. Nitriles underwent reduction to primary amines under optimized conditions at 25 °C using 1 equiv of anhydrous InCl 3 with 3 equiv of NaBH4 in THF. A variety of aromatic, heteroaromatic, and aliphatic nitriles were reduced to their corresponding primary amine in 70-99% isolated yields. Alkyl halide and nitrile functional groups were reduced in tandem by utilizing the reductive capabilities of both HInCl2 and BH3?THF in a one-pot reaction. Finally, the selective reduction of the carbon bromine bond in the presence of nitriles was achieved by generating HInCl2 via the reduction InCl3 with NaBH4 in CH3CN or with lithium dimethylaminoborohydride (MeLAB) in THF.
- Saavedra, Jaime Z.,Resendez, Angel,Rovira, Alexander,Eagon, Scott,Haddenham, Dustin,Singaram, Bakthan
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experimental part
p. 221 - 228
(2012/02/05)
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