In the Search for New Anticancer Drugs, XVI Selective Protection and Deprotection of Primary Amino Groups in Spermine, Spermidine and Other Polyamines

1986 ◽  
Vol 41 (1) ◽  
pp. 122-129 ◽  
Author(s):  
George Sosnovsky ◽  
Jan Lukszo
Keyword(s):  
Anticancer Drugs ◽  
Amino Nitrogen ◽  
Amino Groups ◽  
Selective Protection ◽  
Step Procedure ◽  
One Step ◽  
Primary Amino ◽  
Secondary Amino ◽  
New Anticancer Drugs ◽  
Representative Samples

Abstract Spermidine, spermine and other polyamines 1-5 were selectively protected at the terminal primary amino functions without affecting the secondary amino groups using N-ethoxycarbonyl-phthalimide (15), the Nefkens’ reagent. Three representative products, 17, 18 and 20, readily underwent acylation at the secondary amino nitrogen to give the corresponding compounds 21-26. Selective deprotection of two representative samples 22 and 25 at the primary amino function by hydrazinolysis yielded the corresponding derivatives 27 and 28 with free primary amino groups.In summary, the application of Nefkens’ reagent for the terminal protection of primary amino groups in various polyamines results in a simple, efficient and selective one-step procedure using commercially available reagents.

A Facile Synthesis of Selectively Protected Linear Oligoamines

2003 ◽  
Vol 68 (4) ◽  
pp. 744-750 ◽  
Author(s):  
Simona Koščová ◽  
Miloš Buděšínský ◽  
Jana Hodačová
Keyword(s):  
Nmr Spectra ◽  
Preparative Method ◽  
The Novel ◽  
Amino Groups ◽  
Facile Synthesis ◽  
One Pot ◽  
Primary Amino ◽  
Secondary Amino

A convenient multi-gram preparative method for the synthesis of linear oligoamines having the terminal primary amino groups unprotected and the central secondary amino functions protected with tert-butoxycarbonyl groups is presented. At the same time, simple one-pot preparation of the α,ω-bis(trifluoroacetamide) intermediates 2 has been developed. NMR spectra of the novel selectively protected oligoamines are also discussed.

Synthesis of Phthaloylglycyl Hydrazide Derivatives: Selective Protection of Phthalimide Group from Hydrazinolysis

2018 ◽  
Vol 15 (6) ◽  
pp. 839-845 ◽  
Author(s):  
Ankur Gera ◽  
Chander Mohan ◽  
Sandeep Arora
Keyword(s):  
Amino Acid ◽  
Carboxylic Acid ◽  
Acid Hydrazide ◽  
Acid Group ◽  
Ester Group ◽  
Amino Acid Ester ◽  
Selective Protection ◽  
Step Procedure ◽  
One Step ◽  
Acid Compound

Background: N-phthalimide amino acid hydrazide is a class of compounds that have the potential therapeutic use. In general, hydrazinolysis of N-substituted amino acid(s) ester removes the ester group and yields the corresponding hydrazide. However, in case if N-substitution group is phthalimide, phthalimide group is cleaved and not the ester group. The resulted compound, therefore, is amino acid ester rather than Nphthalimide amino acid hydrazide. The above class of compounds, because of susceptibility of phthalimide group to hydrazinolysis, has previously been synthesized by a lengthy three-step procedure. Objective: N-phthaloylglycyl hydrazide was synthesized by using new efficient, simplified, one step process. Hydrazone derivatives from substituted benzaldehydes, and substituted furaldehyde were also synthesized. Method: N-phthaloylglycyl hydrazide was synthesized from the corresponding carboxylic acid using 1-Ethyl- 3-(3-dimethylaminopropyl)carbodiimide (EDC) as a coupling agent and hydroxybenzotriazole (HOBt) as an activator. Hydrazone derivatives were synthesized by condensation of N-phthaloylglycyl hydrazide with substituted benzaldehyde/substituted furaldehydes. All the compounds were characterized by IR, 1H-NMR, 13CNMR, mass spectroscopy and elemental analysis. Results: The presence of EDC/HOBt resulted in hydrazinolysis of the carboxylic acid group and not the phthalimide group. N-phthaloylglycyl hydrazide was synthesized in good yield. Conclusion: We report the improved process of the synthesis of N-phthaloylglycyl hydrazide. This is the first report where stability of phthaloyl amino acid compound to hydrazine is demonstrated. The reaction may be explored for the reaction schemes where stability of phthalimide group to hydrazinolysis is required.

A facile, one-step method for the determination of accessible surface primary amino groups on solid carriers

2012 ◽  
Vol 44 (10) ◽  
pp. 1309-1313 ◽  
Author(s):  
Zhenyuan Qu ◽  
Hong Xu ◽  
Puwen Ning ◽  
Hongchen Gu
Keyword(s):  
Amino Groups ◽  
Step Method ◽  
One Step ◽  
Primary Amino ◽  
Accessible Surface

Paper ionophoresis of amino compounds. Formation of carbamates, and related reaction

1964 ◽  
Vol 17 (2) ◽  
pp. 256 ◽  
Author(s):  
JL Frahn ◽  
JA Mills
Keyword(s):  
Carbon Dioxide ◽  
Carbon Disulphide ◽  
Amino Nitrogen ◽  
Amino Compound ◽  
Paper Strip ◽  
Amino Groups ◽  
Amino Compounds ◽  
Reactive Groups ◽  
Secondary Amino ◽  
The Stability

Carbamates (N-carboxy derivatives) are formed when solutions of primary or secondary amino compounds in strong alkali are exposed on paper strips to carbon dioxide, and may be separated by paper ionophoresis and detected as additional, anionic components. The formation of mono-, di-, tricarbamates, and so on, from a polyamino compound occurs concurrently, and when an amino compound containing n reactive groups is submitted to paper ionophoresis in 0.lN sodium hydroxide at 18-20� after exposure to carbon dioxide, it affords n additional spots. Most primary and secondary amino groups in saturated compounds, and some aromatic amino groups, are reactive, but highly hindered amino groups are not. Some unreactive groups become reactive when the ionophoresis is conducted at 1-2�. The procedure is analytically useful, and may be used to gain information about the structure of amino compounds. The conditions favouring the formation of carbamates have been defined by paper ionophoresis. The primary reaction in the formation of carbamates is the addition of carbon dioxide to the amino nitrogen atom; carbamates are not formed directly from the carbonate ion. The rate of reaction with carbon dioxide and the stability of the carbamates may be correlated with the steric and electronic environment of the amino groups. Low temperature and high alkalinity are essential for the stability of carbamates in solution.�The "basic mercury carbamates" described by Neuberg and Kerb (Biochem. Z., 1912, 40, 498) do not seem to have the structure assigned by these authors. Dithiocarbamates obtained by reaction of amines with carbon disulphide in alkaline solution are easily identified by paper ionophoresis, but they cannot readily be formed on the paper strip. Attempts to prepare N-sulphinates by reaction of amino compounds with sulphur dioxide on paper strips have been unsuccessful.

Photoimaging Materials Based on Base-amplifying Silicone Resins Having Phenylsulfonylethyl Groups

2006 ◽  
Vol 961 ◽  
Author(s):  
Satoru Inoue ◽  
Koji Arimitsu ◽  
Takahiro Gunji ◽  
Yoshimoto Abe ◽  
Kunihiro Ichimura
Keyword(s):  
Uv Curing ◽  
Exposure Dose ◽  
The Other ◽  
Secondary Amines ◽  
Quantum Yields ◽  
Amino Groups ◽  
Other Hand ◽  
Primary Amino ◽  
Secondary Amino ◽  
Catalyzed Reactions

ABSTRACTRecently, the large number of investigations concerning acid-catalyzed photopolymer systems such as chemically amplified photoresists and UV-curing materials has been reported. On the other hand, analogous systems utilizing base-catalyzed reactions have received far less attention, because low quantum yields for photobase generation to lead to low photosensitivity of these systems. To improve this problem, we proposed introduction of the concept of base proliferation reactions into the photopolymer systems using base-catalyzed reactions. The concept involves the autocatalytic base-catalyzed decomposition of a compound, referred to as a base amplifier which releases a newborn amine, leading to its autocatalytic decomposition. In fact, the addition of the base amplifiers such as 9-fluorenylmethyl carbamate, phenylsulfonylethyl carbamate, and 3-nitropentane-2-yl carbamate to a photopolymer consisting of an epoxy polymer sensitized and a photobase generator (PBG) resulted in the marked improvement of photosensitivity.However, these base amplifiers with low molecular weight are not suitable for photopatterning because of the volatility and the excessive diffusion of amines proliferated in polymer films. We report here novel base-amplifying silicone resins tethering phenylsulfonylethyl carbamoyl groups which proliferate primary amino groups or secondary amino groups in their side chains.Base-catalyzed decomposition behavior of films of these resins containing PBG was evaluated by UV absorption measurements. A film consisting of the resin proliferating primary amino groups and 10 wt% of PBG decomposed immediately in a nonlinear manner by 365 nm irradiation and subsequent heat treatment at 120oC for 6 min. On the other hand, this film without UV irradiation was thermally stable for 18 min at 120oC. These results indicate that photoinduced base proliferation reaction of the resin proceeded. A film consisting of the resin generating secondary amino groups and PBG decomposed in a way similar to that of the resin proliferating primary amino groups. Furthermore, lithographic evaluation of the film comprising the resin to generate secondary amines and PBG obtained 7ÊS positive images with an exposure dose of 75 mJ/cm2 which shows higher sensitivity when compared to conventional base-catalyzed photopolymers.

scholarly journals ANALYSIS OF AMINE HARDENERS FOR ADHESIVE USING pH-METRIC TITRATION IN MICELLAR MEDIA OF SODIUM DODECYLSULFATE

2020 ◽  
pp. 27-29
Author(s):  
V. Starova
Keyword(s):  
Epoxy Resins ◽  
Cetylpyridinium Chloride ◽  
Sodium Dodecylsulfate ◽  
Polymerization Reaction ◽  
Amino Groups ◽  
Exact Mass ◽  
Titration Curves ◽  
Ph Jump ◽  
Primary Amino ◽  
Secondary Amino

One of the primary tasks in the development of amine hardeners for adhesive and epoxy resins is the control of amino group quantities in their composition. The main parameter that indicates the rate of the polymerization reaction and characterizes the quality of the hardener is the amine number. It is determined by the number of primary and secondary amino groups contained in the hardener molecule, because these functional groups are involved in reactions with epoxy resins. The most common methods of analysis of amine hardeners are mainly based on titration in organic solvents and require a procedure of derivatization of primary and secondary amino groups using formaldehyde and acetic anhydride. The search for a simple, cheap and environmentally friendly alternative to such titrimetric methods is still ongoing. In this paper on the example of industrial samples of polyamide PO-300, polyethylene polyamine (PEPA) and diethylenetriamine (DETA) shows the prospects of using the method of pH-metric titration in water-micellar medium of sodium dodecylsulfate (SDS) to determine the content of primary and secondary amino groups in the adhesive hardeners. According to the developed techniques, working solutions of PO-300, PEPA and DETA were prepared by dissolving their exact mass in 20 ml of 2.0 M SDS solution. The values of PO-300, PEPA and DETA samples were 0.1040 g, 0.0225 g and 0,0200 g, respectively. Titration of the obtained solutions was performed with 0.05 M HCl solution. The percentage of primary amino groups, calculated on the basis of the obtained differential titration curves, is equal to 5,56% for PO-300, 23,6% for PEPA and 31,6% for DETA. The content of secondary amino groups in PO-300, PEPA and DETA samples is 3,03%, 15,0% and 19,6%. Founded amine number for PO-300, PEPA and DETA is well correlated with data declared by the manufacturer and equals to 302, 1381 and 1890, respectively. Unfortunately, it was not possible to establish the presence and quantity of tertiary amino groups in the samples of adhesive hardeners by this technique. The effect of cationic surfactant cetylpyridinium chloride, nonionic Triton X-100 and anionic surfactant SDS on the value of the pH jump of diethylenetriamine (DETA) was also studied. It was found that anionic SDS has the greatest differentiating effect on the acid-base properties of amino groups DETA in comparison with other studied surfactants. At that, the primary amino groups are titrated in the first place.

scholarly journals CRYSTALLINE ACETYL DERIVATIVES OF PEPSIN

1934 ◽  
Vol 18 (1) ◽  
pp. 35-67 ◽  
Author(s):  
Roger M. Herriott ◽  
John H. Northrop
Keyword(s):  
Specific Activity ◽  
Amino Nitrogen ◽  
Strong Acid ◽  
Acetyl Derivative ◽  
Crystal Form ◽  
Amino Groups ◽  
Acetyl Content ◽  
Titration Curves ◽  
Primary Amino ◽  
Derivatives Of

Crystalline pepsin has been acetylated by the action of ketene in aqueous solution at pH 4.07–5.5. As acetylation proceeds the activity decreases, the decrease being more rapid at pH 5.0–5.5 than at 4.0–4.5. Three acetyl derivatives have been isolated from the reaction mixture and obtained in crystalline form. The crystal form of these derivatives is similar to that of pepsin. Fractionation and solubility determinations show that these preparations are not mixtures or solid solutions of the original pepsin with an inactive derivative. A compound which contains three or four acetyl groups and which has lost all of its original primary amino groups can be isolated after short acetylation. It has the same activity as the original pepsin. A second derivative containing six to eleven acetyl groups has also been isolated. It has about 60 per cent of the activity of the original pepsin. A third derivative having twenty to thirty acetyl groups and about 10 per cent of the activity of original pepsin can be isolated after prolonged acetylation. The 60 per cent active derivative on standing in strong acid solution loses some of its acetyl groups and at the same time regains the activity of the original pepsin. The compound obtained in this way is probably the same as the completely active three acetyl derivative obtained by mild acetylation. These results show that acetylation of three or four of the primary amino groups of pepsin causes no change in the specific activity of the enzyme but that the introduction of acetyl groups in other parts of the molecule results in a marked loss in activity. The solubilities, amino nitrogen content, acetyl content, isoelectric point, and the specific activity have been determined by a variety of methods and found to be different from the corresponding properties of crystalline pepsin. The pH-activity curves, acid and alkali inactivation, and titration curves were not significantly different from the same respective properties of pepsin.

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