234. The dissociation constants of organic acids. Part IX. Some amic acids

Jeffery, George H.; Vogel, Arthur I.

doi:10.1039/jr9340001101

Cited by 22 publications

(11 citation statements)

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“…The precipitate was collected and recrystallized from water: Yield, 4.1 g; mp 156-158 °C. The literature melting point of this compound is 156-158 °C (14). Glutaramic Acid.…”

Section: Methodsmentioning

confidence: 99%

Colorimetric hydroxylamine-iron(III) methods for studies of the enzymic hydrolyses of cyclic imides and of amic acids

Maguire¹,

Dudley²

1977

Anal. Chem.

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“…The precipitate was collected and recrystallized from water: Yield, 4.1 g; mp 156-158 °C. The literature melting point of this compound is 156-158 °C (14). Glutaramic Acid.…”

Section: Methodsmentioning

confidence: 99%

Colorimetric hydroxylamine-iron(III) methods for studies of the enzymic hydrolyses of cyclic imides and of amic acids

Maguire¹,

Dudley²

1977

Anal. Chem.

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“…b After 48 h. ‡ The σ*-value for the carbamoylmethyl group is estimated to be ϩ0.59 according to the following equation, 13 pK a (RCO 2 H) = Ϫ1.700σ*(R) ϩ 4.644, by employing the reported K a -value for propanedioic acid monoamide (2.284 × 10 Ϫ4 at 25 ЊC). 14 esters whose amide hydrogens were substituted by methyl group(s) were examined next (Entries 30 and 31 in Table 1).…”

Section: Resultsmentioning

confidence: 99%

Broadening of the substrate tolerance of α-chymotrypsin by using the carbamoylmethyl ester as an acyl donor in kinetically controlled peptide synthesis

Miyazawa

Tanaka

Ensatsu

et al. 2001

J. Chem. Soc., Perkin Trans. 1

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In the kinetically controlled approach of peptide synthesis mediated by α-chymotrypsin, the broadening of the protease's substrate tolerance is achieved by switching the acyl donor from the conventional methyl ester to the carbamoylmethyl ester. Thus, as a typical example, the extremely low coupling efficiency obtained by employing the methyl ester of an inherently poor amino acid substrate, Ala, is significantly improved by the use of this particular ester. Its ameliorating effect is observed also in the couplings of other amino acid residues such as Gly and Ser as carboxy components.

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“…Insoluble dark-red precipitate (1.1 g) was treated with 5 ml of 5% HCl, thoroughly stirred, evaporated at a reduced pressure, the residue was recrystallized from 2-propanol. Yield 0.55 g (44% ), mp 158-160°C (mp 157°C [10] N-(Trifluoromethylsulfonyl)phthalamide (VIIIb). To a dispersion of 0.5 g (3 mmol) of phthalimide in a mixture of 10 ml of 2-propanol and 2 ml of MeOH was added by small portions 1.4 g (8 mmol) of triflamide sodium salt.…”

Section: -Amino-4-oxobutanoic Acid (Viiia)mentioning

confidence: 99%

Reaction of γ-dicarboxylic acids amides and imides with trifluoromethanesulfonamide and formaldehyde

2009

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Three-component condensation of trifluoromethanesulfonamide with paraformaldehyde and succinamide depending on the reaction conditions led alongside bis(trifluoromethanesulfonamido)methane to the formation of a substitution product, bis[(trifluoromethylsulfonyl)aminomethyl]succinamide, or to a cyclization product, N-[trifluoromethylsulfonyl)aminomethyl]succinimide. The attempt to obtain the latter by the reaction of the trifluoromethanesulfonamide sodium salt CF 3 SO 2 NHNa with N-chloromethylsuccinimide unexpectedly resulted in N,N-bis(succinimidomethyl)-trifluoromethanesulfonamide. Analogously the reaction of CF 3 SO 2 NHNa with N-chloromethyl-phthalimide gave N,N-bis(phthalimidomethyl)trifluoromethanesulfonamide. The reaction of CF 3 SO 2 NHNa with succinimide and phthalimide in water and alcohol solution resulted in the ring opening and further transformation of the formed monosubstituted N-(trifluoromethylsulfonyl)amides of succinic and phthalic acids.We showed formerly that the condensation of trifluoromethanesulfonamide (triflamide) CF 3 SO 2 NH 2 with paraformaldehyde depending on the reaction conditions led to the formation of versatile linear and cyclic products [1,2]. Also the three-component reactions of triflamide with paraformaldehyde and various amides were investigated, and in some events mixed condensation products were obtained [3]. It was shown in particular that the reaction of triflamide, paraformaldehyde, and malonamide provided a spirocyclic condensation product involving both amido groups and the methylene group of the malonamide, 4,10-bis-(trifluoromethylsulfonyl)-2,4,8,10-tetraazaspiro-[5,5]undecane-1,7-dione [3]. In extension of this research the present study consists in the investigation of the reaction of succinamide, succinimide, and phthalimide with trifluoromethanesulfonamide and formaldehyde under various conditions.The investigation of the transformations in the system trifluoromethanesulfonamide-formaldehyde−succinamide (I) revealed the fundamental dependence of the reaction direction on its conditions. In the medium of concn. H 2 SO 4 alongside the unreacted triflamide and the linear product of its condensation with formaldehyde [bis(trifluoromethanesulfonamido)methane (II)] the formation was found of a product of the triple condensation at both amido groups, bis[(trifluoromethylsulfonyl)aminomethyl]-succinamide (III) that was isolated after washing the reaction product II with a mixture ether-hexane and was recrystallized from dichloromethane.The same reaction carried out in ethyl acetate in the presence of sulfuric acid alongside compound II unexpectedly furnished a cyclic amidomethylation product, N-[(trifluoromethylsulfonyl)aminomethyl]succinimide (IV) isolated analogously and recrystallized from chloroform.The structure of compound III was proved by the presence in its 1 H NMR spectrum of a singlet from CH 2 CH 2 group at 2.36 ppm, a broadened singlet of NHSO 2 , a triplrt of NHCO, and a doublet of NCH 2 N in the ratio 2:1:1:2, and of the corresponding signals in the 13 C...

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234. The dissociation constants of organic acids. Part IX. Some amic acids

Cited by 22 publications

References 0 publications

Colorimetric hydroxylamine-iron(III) methods for studies of the enzymic hydrolyses of cyclic imides and of amic acids

Colorimetric hydroxylamine-iron(III) methods for studies of the enzymic hydrolyses of cyclic imides and of amic acids

Broadening of the substrate tolerance of α-chymotrypsin by using the carbamoylmethyl ester as an acyl donor in kinetically controlled peptide synthesis

Reaction of γ-dicarboxylic acids amides and imides with trifluoromethanesulfonamide and formaldehyde

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