The Aminolysis of Esters. A Preliminary Study

Baltzly, Richard; Berger, Irving M.; Rothstein, Arnold A.

doi:10.1021/ja01165a086

Cited by 31 publications

(22 citation statements)

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“…Dimethylamine, piperidine and morpholine reacted slowly with the reactive ester methyl lactate (25) but amines with the nitrogen substituent larger than methyl did not react at all (28,32) even when sodium methoxide was used as the catalyst (32). Sodium methoxide was found to accelerate the rate of the reaction of methyl acetate with both piperidine and morpholine, however (9). With no catalyst and at high temperatures fatty morpholides formed (33) and even hindered dialkylamines were found to react with aliphatie esters at 250~ (20).…”

Section: Part II Secondary Amine Aminolysismentioning

confidence: 99%

“…None of these reports presented a study of optimum reaction conditions. In investigations of the kinetics of the anfinolysis of esters at low temperatures (9,10,11,12), a marked increase in the rate of reaction by alk- oxide ion has been shown, but practical preparative conditions were not given. In the absence of any taralyst, high reaction temperatures (150~176 were often necessary to convert esters to amides rapidly and the use of pressure equipment with volatile amines was required (13,14,15,16,17,18,19,20).…”

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confidence: 99%

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Low temperature aminolysis of methyl stearate catalyzed by sodium methoxide

Jordan

Port

1961

J Am Oil Chem Soc

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Aminolysis of methyl stearate by both primary and secondary amine catalyzed by sodium methoxide was found to be rapid at 30ŶC. under anhydrous conditions. With primary amines under optimum conditions (mole ratio to ester: amine, 10; catalyst, 0.12), the minimum reaction times necessary to obtain yields of amide over 90% were:n‐butylamine, 30 min.;iso‐butyl‐, 1 hour; allyl‐, 1.8 hr.; benzyl‐, 3.2 hr.;sec‐butyl‐, 16 hr.; ammonia (a heterogenous reaction requiring an optimum triethylamine to ester ratio of 2 ml./g. and a catalyst mole ratio of 0.20) 2 days. Secondary amines reacted rapidly at 30ŶC. (15 min. to 24 hr. for a 90% yield of amide) when the nitrogen atom was joined into a saturated ring or held at least one methyl group, but very slowly even at 100ŶC, when the substituent was dialkyl larger than methyl. Uncatalyzed, all reactions were extremely slow.

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Section: Part II Secondary Amine Aminolysismentioning

confidence: 99%

mentioning

confidence: 99%

Low temperature aminolysis of methyl stearate catalyzed by sodium methoxide

Jordan

Port

1961

J Am Oil Chem Soc

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“…N U~IEROUS KINETIC INVESTIGATIONS have been made to elucidate the mechanism of ester aminolysis (1)(2)(3)(4)(5)(6)(7)(8)(9)(10). These investigations have revealed the effect of structure on reactivity (4), have demonstrated the influence of solvents (3,4), including water (2,7-10) on rate, and have shown that the reaction is subject to both acid (2) and base catalysis (1,3,(5)(6)(7)(8)(9)(10). Particularly noteworthy has been the strong accelerating influence of alkoxide catalysis (t, 3,5,6) in nonaqueous systems.…”

Section: Introductionmentioning

confidence: 99%

“…These investigations have revealed the effect of structure on reactivity (4), have demonstrated the influence of solvents (3,4), including water (2,7-10) on rate, and have shown that the reaction is subject to both acid (2) and base catalysis (1,3,(5)(6)(7)(8)(9)(10). Particularly noteworthy has been the strong accelerating influence of alkoxide catalysis (t, 3,5,6) in nonaqueous systems. Acceleration of this normally slow reaction by alkoxide catalysis has been used successfully in preparative work (11) even with aromatic amines (12) and was found to be especially useful when volatile amines were reacted with fatty esters at room temperature (13).…”

Section: Introductionmentioning

confidence: 99%

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Kinetics of the aminolysis of hydrogenated tallow by allylamine and other primary amines in methanol

Jordan

Artymyshyn

Eddy

et al. 1966

J Americ Oil Chem Soc

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Kinetics of the aminolysis of hydrogenated tallow by allylamine in methanol solution under sodium methoxide catalysis was studied at several temperatures (60 to 90C) and catalyst concentrations. Under the experimental conditions the triglycerides were rapidly converted to the mixed methyl esters, which slowly reacted with the amine to produce the mixed amides. At constant catalyst concentration, disappearance of triglyceride was found to be first order in triglyceride and in amine. Because rate was found to be directly proportional to catalyst concentration, the experimental over-all rate was --d[Triglyceride]/dt = ka [Triglyceride] [Amine] [RO-], and k3 was 2.022 kg ~ mole -2 hr 1. A rneehanism proposed by Bunnett and Davis for ester aminolysis involving an ester-amine complex formed in a rapid pre-transition-state equilibrium is consistent with thermodynamic terms which reconcile a large negative entropy of activation (--44.17 cal deg -1 equivalent 1) and relatively small energy of activation (11.60 kcal equivalent-1). Relative rate constants at 70C under sodium-methoxide catalysis for the aminolysis of hydrogenated tallow by a variety of structurally different primary amines agreed, in general, with those found by others for the ethylene glycol-catalyzed reaction of methyl acetate with the same amines at 25C: However, monoethanolamine reacted nineteen times faster than predicted, which suggested a mechanism involving initial attack by the alkoxy anion of the ethanolamine in the rate detering step, followed by rapid, base-catalyzed, acyl acyl oxygen-to-nitrogen (O ---> N) migration. The velocity constants and thermodynamic constants reported enable prediction of the time required for specific yields under a variety of experimental conditions. ProcedureReactions were conducted in 25-ml flasks which were charged with hydrogenated tallow (about 1.2 eq/kg), a slight excess of amine (1.18 moles per equivalent of ester), freshly made 2 N sodium methoxide solution (13), and dry methanol, and then sealed and heated in a constant temperature bath. Reaction

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Graft polymerization of methacrylic acid onto polytetrafluoroethylene initiated by alkyllithium/electron‐donating solvents

Okuda

Hayashi

Sakurai

et al. 2004

J of Applied Polymer Sci

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Graft polymerization of methacrylic acid (MAA) onto polytetrafluoroethylene (PTFE), initiated by the mixed solution of alkyllithium/hexamethylphosphoramide (HMPA) at low temperature, was studied. Using electron spin resonance (ESR), nuclear magnetic resonance, X-ray photoelectron and vibrational (infrared) spectroscopies, the chemical structure of the grafted poly(methacrylic acid) (PMAA) onto the PTFE (PTFE-g-PMAA) was investigated. The grafted PMAA was found to be located deeper than 2.5 nm from the surface of the PTFE. The molecular motion of the PTFE-g-PMAA was also studied by means of the temperature-dependent ESR spectra of the spin-labeled PTFEg-PMAA. The results suggested that the molecular motion of the grafted PMAA chain was mainly controlled by that of the principal PTFE chain, and the evaluated activation energy was lower for the grafted PMAA chain (e.g., 6.5 kJ/mol at temperature range below 295 K) than that for the PMAA homopolymer (13.2 kJ/mol).

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The Aminolysis of Esters. A Preliminary Study

Cited by 31 publications

References 0 publications

Low temperature aminolysis of methyl stearate catalyzed by sodium methoxide

Low temperature aminolysis of methyl stearate catalyzed by sodium methoxide

Kinetics of the aminolysis of hydrogenated tallow by allylamine and other primary amines in methanol

Graft polymerization of methacrylic acid onto polytetrafluoroethylene initiated by alkyllithium/electron‐donating solvents

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