18300-91-9Relevant articles and documents
Method for preparing nitrile by reacting acetone cyanohydrin with haloalkane
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Paragraph 0043-0049; 0051-0057; 0070, (2019/08/20)
The invention provides a method for preparing nitrile by reacting acetone cyanohydrin with haloalkane. According to the invention, by using acetone cyanohydrin as a cyaniding reagent, the problems, such as long reaction time, low yield, strict reaction conditions and the like enchanted in an existing preparation method in which highly toxic sodium cyanide or potassium cyanide or expensive trimethylsilyl cyanide is used as a cyanogen source, are solved. The method comprises the following steps: dissolving acetone cyanohydrin in a mixed solvent of a high boiling point dipolar aprotic solvent anda low boiling point aprotic solvent, adding a catalyst lithium hydroxide, stirring at 25-50 DEG C for one hour and then adding a haloalkane for continuous reaction for 2-3 hours; next, adding saturated saline water for washing twice, separating out an organic layer, and boiling off the solvent after drying, thereby obtaining a nitrile compound. The method for preparing a nitrile compound disclosed in the invention is characterized by low reaction toxicity, simple process, easy of operation, low production cost, and a yield of more than 95%.
Thiol-Catalyzed Radical Decyanation of Aliphatic Nitriles with Sodium Borohydride
Kawamoto, Takuji,Oritani, Kyohei,Curran, Dennis P.,Kamimura, Akio
supporting information, p. 2084 - 2087 (2018/04/16)
Radical decyanation of aliphatic nitriles was achieved in the presence of NaBH4 and a thiol. The reaction proceeds via a radical mechanism involving borane radical anion addition to nitrile to form an iminyl radical, which undergoes carbon-carbon cleavage. Reductive radical addition to acrylonitrile is followed by decyanation to give a two-carbon homologated product in a net radical ethylation reaction.
Effect of heteroatom insertion at the side chain of 5-alkyl-1H-tetrazoles on their properties as catalysts for ester hydrolysis at neutral pH
Bhattacharya, Santanu,Vemula, Praveen Kumar
, p. 9677 - 9685 (2007/10/03)
Herein we introduce tetrazole and its suitably designed derivatives as powerful ester-cleaving reagents. By first performing a detailed ab initio computational study, we found that, in the side chain of 5-alkyl-1H-tetrazoles, introduction of a heteroatom (e.g., N, O, or S at the α-position of the tetrazole ring) raises the charge on the tetrazole nucleus significantly. All calculations have been performed using restricted Hartree-Fock (RHF) and hybrid ab initio/DFT (B3LYP) methods employing 6-31G* and 6-31+G* basis sets. To estimate the nucleophilicity of these reagents, the charges on conjugate bases of various tetrazole derivatives have been calculated using natural population (NBO) analysis in gas phase and in water. Free energy of protonation (fep) of the 1H-tetrazole derivatives (1-7), free energy of solvation, ΔGaq, and the corresponding pKa values have been calculated by self-consistent reaction field (SCRF) methods applying the polarized continuum model (PCM). Since the calculation indicates that incorporation of heteroatom leads to enhanced nucleophilicity in their deprotonated anionic tetrazole forms, a series of 5-substituted 1H-tetrazole derivatives have been synthesized. These compounds indeed catalyze the hydrolysis of p-nitrophenyl diphenyl phosphate (PNPDPP) and p-nitrophenyl hexanoate (PNPH) efficiently in cationic cetyl trimethylammonium bromide (CTABr) micelles at pH 7.0 and 25 °C. The pseudo-first-order rate constants (k obs) were determined for each catalyst against both substrates. The experimental and theoretical results show that, to achieve better k obs values for the cleavage of PNPDPP and PNPH under micellar conditions, charge on the N- atom (nucleophile) of conjugate base is important. Replacing the α-CH2 in alkyl substituent with S (3), NH (4), or O (5) enhances the accumulation of charge on N- in conjugate bases of tetrazoles and subsequently increases their intrinsic nucleophilic reactivity toward hydrolytic reactions. Significantly large rate enhancements were observed for the cleavage of PNPDPP and PNPH at pH 7.0 in the presence of catalytic system 5/CTABr over background (only CTABr). Tetrazole 4 (α-isomer) showed 4-5-fold superior reactivity over 6 (β-isomer) under identical conditions. Natural charges obtained from NBO analysis (B3LYP/ 6-31+G*) are -0.94 and -0.852 on N- in the conjugate bases of 4 and 6, respectively. This also predicts that 4 is a better nucleophile than 6. All the newly synthesized tetrazole derivatives in micellar media display true catalytic properties by cleaving several fold excess of substrates.
