19202-02-9

Upstream product

• 98-88-4 benzoyl chloride 
• 626-56-2 3-Methylpiperidine 
• 959-22-8 p-nitrophenylbenzoate 
• 1523-15-5 2,4-dinitrophenyl benzoate 
• 1000789-21-8 C₁₂H₁₇NS 
• 5005-35-6 2-pyridyl benzoate 
• 37593-94-5 4-chloro-2-nitrophenyl benzoate 
• 36228-61-2 4-(Benzoyloxy)pyridine 

Downstream Products

• 25118-31-4 (+/-)-2-methyl-1,5-dibromopentane 
• 100-47-0 benzonitrile 
• 19980-02-0 (3-hydroxy-3-methylpiperidin-1-yl)(phenyl)methanone 

Relevant academic research and scientific papers

Kinetic study on aminolysis of y-substituted-phenyl x-substituted- benzoates: Effects of substituents x and y on reactivity and reaction mechanism

A kinetic study on aminolysis of 2-chloro-4-nitrophenyl X-substituted-benzoates (2a-k) in 80 mol % H2O/20 mol % DMSO at 25.0 oC is reported. The Bronsted-type plot for the reactions of 2-chloro-4-nitrophenyl benzoate (2g) with a series of cyclic secondary amines curves downward (e.g., β1 = 0.25, β2 = 0.85 and pKa o = 10.3), which is typical of reactions reported to proceed through a stepwise mechanism with a change in ratedetermining step (RDS). The Hammett plot for the reactions of 2a-k with piperidine consists of two intersecting straight lines, while the corresponding Yukawa-Tsuno plot exhibits an excellent linear correlation with ρX = 1.15 and r = 0.59. Thus, it has been concluded that the nonlinear Hammett plot is not due to a change in RDS but is caused by stabilization of substrates through resonance interactions between the electron-donating substituent and the C=O bond. Substrates possessing a substituent at the 2-position of the leaving aryloxide deviate negatively from the curved Bronsted-type plot for the reactions of Y-substituted-phenyl benzoates (3ai), implying that the steric hindrance exerted by the substituent at the 2-position is an important factor which governs the reactivity of Y-substituted-phenyl benzoates.

Comparison of aminolysis of 2-pyridyl and 4-pyridyl x-substituted benzoates in acetonitrile: Evidence for a concerted mechanism involving a cyclic transition state

A kinetic study on reactions of 2-pyridyl X-substituted benzoates (6a-i) with a series of cyclic secondary amines in MeCN is reported. The Hammett plot for the reaction of 6a-i with piperidine consists of two intersecting straight lines while the Yukawa-Tsuno plot exhibits an excellent linear correlation with ρX = 1.28 and r = 0.63, indicating that the nonlinear Hammett plot is not caused by a change in the rate-determining step but rather by resonance stabilization of substrates possessing an electron-donating group (EDG) in the benzoyl moiety. The Bronsted-type plots are linear with βnuc = 0.59 ± 0.02, which is typical of reactions reported to proceed through a concerted mechanism. A cyclic transition state (TS), which forces the reaction to proceed through a concerted mechanism, is proposed. The deuterium kinetic isotope effect of 1.3 ± 0.1 is consistent with the proposed mechanism. Analysis of activation parameters reveals that ΔH? increases linearly as the substituent X changes from an electron-withdrawing group (EWG) to an EDG, while TΔS ? remains nearly constant with a large negative value. The constant TΔS? value further supports the proposal that the reaction proceeds through a concerted mechanism with a cyclic TS.

N-tosyl-(S)-prolyl chloride in kinetic resolution of racemic heterocyclic amines

The kinetic resolution of racemic heterocyclic amines via acylation with N-tosyl-(S)-prolyl chloride was systematically investigated. It was established that racemic mixtures of aromatic amines could be resolved with high efficiency, while the acylation of 2- and 3-methylpiperidines occurred with low diastereoselectivity. A method for the preparation of enantiomerically pure (3R)-7,8-difluoro-3-methyl-3,4-dihydro-2H-[1,4]benzoxazine was developed.

Kinetic study on aminolysis of 2-chloro-4-nitrophenyl x-substituted-benzoates in acetonitrile and in H2O Containing 20mol% DMSO: Effects of medium and substituent X on reactivity and reaction mechanism

Second-order rate constants for reactions of 2-chloro-4-nitrophenyl X-substituted-benzoates 1a-1j with a series of cyclic secondary amines in MeCN have been measured. Comparison of the kinetic results with those reported previously for the corresponding reactions carried out in H2O containing 20 mol % DMSO has revealed that amines are less reactive in MeCN. The Bronsted-type plot for the aminolysis of 2-chloro-4-nitrophenyl benzoate (1f) in MeCN is linear with βnuc= 0.64, which is in contrast to the curved Bronsted-type plot reported for the reaction performed in the H2O-DMSO misxture. The Hammett plot for the reactions of 1a-1j with piperidine consists of two intersecting straight lines while the Yukawa-Tsuno plot exhibits an excellent linear correlation with ρX= 1.22 and r = 0.60, indicating that the nonlinear Hammett plot is not due to a change in rate-determining step but is caused by stabilization of substrates possessing an electron-donating substituent through resonance interactions between the substituent and the carbonyl functionality. It has been concluded that medium change from the H2O-DMSO mixture to MeCN forces the aminolysis of 1a-1j to proceed through a concerted mechanism by destabilizing the zwitterionic tetrahedral intermediate (T±).

Kinetic study on aminolysis of 4-pyridyl X-substituted benzoates: Effect of substituent X on reactivity and reaction mechanism

A kinetic study is reported for nucleophilic substitution reactions of 4-pyridyl X-substituted benzoates 7a-e with a series of alicyclic secondary amines in H2O. The Bronsted-type plot for the reactions of 4-pyridyl benzoate 7c is linear with βnuc = 0.71. The corresponding reactions of 2-pyridyl benzoate 6, which is less reactive than 7c, resulted in also a linear Bronsted-type plot with βnuc = 0.77. The fact that the more reactive 7c results in a smaller βnuc value appears to be in accord with the reactivity- selectivity principle. The aminolysis of 7c has been suggested to proceed through a stepwise mechanism in which breakdown of the intermediate is the rate-determining step (RDS). The Hammett plot for the reactions of 7a-e with piperidine consists of two intersecting straight lines, i.e., ρX = 1.47 for substrates possessing an electron-donating group (EDG) and ρX = 0.91 for those possessing an electron-withdrawing group (EWG). In contrast, the corresponding Yukawa- Tsuno plot exhibits excellent linear correlation with ρX = 0.79 and r = 0.56. Thus, it has been concluded that the nonlinear Hammett plot is not due to a change in the RDS but is caused by stabilization of the ground state of the substrates possessing an EDG through resonance interaction between the EDG and the C=O bond of the substrates.

A kinetic study on aminolysis of 2-pyridyl X-substituted benzoates: Effect of changing leaving group from 4-nitrophenolate to 2-pyridinolate on reactivity and mechanism

Second-order rate constants (kN) have been measured spectrophotometrically for nucleophilic substitution reactions of 2-pyridyl X-substituted benzoates 8a-e with a series of alicyclic secondary amines in H2O at 25.0 ± 0.1 °C. The kN values for the reactions of 8a-e are slightly smaller than the corresponding reactions of 4-nitrophenyl X-substituted benzoates 1a-e (e.g., kN 1a-e/kN8a-e = 1.1 3.1), although 2-pyridinolate in 8a-e is ca. 4.5 pKa units more basic than 4-nitrophenolate in 1a-e. The Bronsted-type plot for the aminolysis of 8c (X = H) is linear with βnuc = 0.77 and R2 = 0.991 (Figure 1), which is typical for reactions reported previously to proceed through a stepwise mechanism with breakdown of a zwitterionic tetrahedral intermediate T± being the rate-determining step (RDS), e.g., aminolysis of 4-nitrophenyl benzoate 1c. The Hammett plot for the reactions of 8a-e with piperidine consists of two intersecting straight lines (Figure 2), i.e., ρ = 1.71 for substrates possessing an electron-donating group (EDG) while ρ = 0.86 for those bearing an electron-withdrawing group (EWG). Traditionally, such a nonlinear Hammett plot has been interpreted as a change in RDS upon changing substituent X in the benzoyl moiety. However, it has been proposed that the nonlinear Hammett is not due to a change in RDS since the corresponding Yukawa-Tsuno plot exhibits excellent linear correlation with ρ = 0.85 and r = 0.62 (R2 = 0.995, Figure 3). Stabilization of substrates 8a-e in the ground state has been concluded to be responsible for the nonlinear Hammett plot.

5-Exo versus 6-Endo cyclization of primary aminyl radicals: An experimental and theoretical investigation

(Chemical Equation Presented) The cyclization of neutral primary pent-4-enylaminyl radicals was investigated experimentally and theoretically. Unlike the corresponding secondary aminyl radicals, primary pent-4-enylaminyl radicals underwent efficient cyclization to afford the pyrrolidine and/or piperidine products in good to high yields. While the simple pent-4-enylaminyl radical gave predominately the 5-exo cyclization product, 4-chloropent-4- enylaminyl radicals led to the formation of the corresponding 6-endo cyclization products in excellent regioselectivity. Theoretical calculations revealed that the 5-exo cyclization rate of primary aminyl radicals is about 3-4 orders of magnitude higher than that of secondary aminyl radicals.

Effects of amine nature and nonleaving group substituents on rate and mechanism in aminolyses of 2,4-dinitrophenyl x-substituted benzoates

Second-order rate constants have been measured for the reactions of 2,4-dinitrophenyl X-substituted benzoates (1a-f) with a series of primary amines in 80 mol % H2O/20 mol % DMSO at 25.0 ± 0.1 °C. The Bronsted-type plot for the reactions of 1d with primary amines is biphasic with slopes β1 = 0.36 at the high pKa region and β2 = 0.78 at the low pKa region and the curvature center at pKa° = 9.2, indicating that the reaction proceeds through an addition intermediate with a change in the rate-determining step as the basicity of amines increases. The corresponding Bro nsted-type plot for the reactions with secondary amines is also biphasic with β1 = 0.34, β2 = 0.74, and pKa° = 9.1, indicating that the effect of amine nature on the reaction mechanism and pKa° is insignificant. However, primary amines have been found to be less reactive than isobasic secondary amines. The microscopic rate constants associated with the aminolysis have revealed that the smaller k 1 for the reactions with primary amines is fully responsible for their lower reactivity. The electron-donating substituent in the nonleaving group exhibits a negative deviation from the Hammett plots for the reactions of 1a-f with primary and secondary amines, while the corresponding Yukawa-Tsuno plots are linear. The negative deviation has been ascribed to stabilization of the ground state of the substrate through resonance interaction between the electron-donating substituent and the carbonyl functionality.

Addition-Elimination Mechanism of Aminolyses of 4-Nitrophenyl Benzoate and Its Sulfur Analogue

The aminolysis of O-(4-nitrophenyl) thiobenzoate proceeds via an addition-elimination mechanism in which the rate-determining step is dependent on both concentration and basicity of amines.

NMR Spectra and Stereochemistry of N-Acetyl and N-Benzoyl Derivatives of Solasodine

N-Acetylation of solasodine gives only one rotameric N-acetyl derivative compared with N-acetyl-3-methylpiperidine, which exists in solution as two equally populated rotamers.The 1H and 13C NMR spectra (CDCl3) of O,N-diacetyl- and O-acetyl-N-benzoylsolasodine indicate significant deviations from F-ring chair geometry.Opening of the F ring of these derivatives in CDCl3 solution at 25 deg C, to give the corresponding furosta-5,20(22)-diene derivatives, was ascertained by NMR spectroscopy.Key Words: Solasodine O,N-Diacetylsolasodine O-Acetyl-N-benzoylsolasodine 3β-Acetoxy-26-acetamidofurosta-5,20(22)-diene 3β-Acetoxy-26-benzamidofurosta-5,20(22)-diene