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.

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.

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.

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.

Aldehyde gold clusters for molecular labeling

1995 ◽  
Vol 53 ◽  
pp. 858-859
Author(s):  
James F. Hainfeld ◽  
Frederic R. Furuya
Keyword(s):  
Covalent Bond ◽  
Aldehyde Group ◽  
Gold Clusters ◽  
Side Reactions ◽  
Amino Groups ◽  
Sodium Cyanoborohydride ◽  
Schiff’S Base ◽  
Protein Molecules ◽  
Hydroxysuccinimide Esters ◽  
Primary Amino

Glutaraldehyde is a useful tissue and molecular fixing reagents. The aldehyde moiety reacts mainly with primary amino groups to form a Schiff's base, which is reversible but reasonably stable at pH 7; a stable covalent bond may be formed by reduction with, e.g., sodium cyanoborohydride (Fig. 1). The bifunctional glutaraldehyde, (CHO-(CH2)3-CHO), successfully stabilizes protein molecules due to generally plentiful amines on their surface; bovine serum albumin has 60; 59 lysines + 1 α-amino. With some enzymes, catalytic activity after fixing is preserved; with respect to antigens, glutaraldehyde treatment can compromise their recognition by antibodies in some cases. Complicating the chemistry somewhat are the reported side reactions, where glutaraldehyde reacts with other amino acid side chains, cysteine, histidine, and tyrosine. It has also been reported that glutaraldehyde can polymerize in aqueous solution. Newer crosslinkers have been found that are more specific for the amino group, such as the N-hydroxysuccinimide esters, and are commonly preferred for forming conjugates. However, most of these linkers hydrolyze in solution, so that the activity is lost over several hours, whereas the aldehyde group is stable in solution, and may have an advantage of overall efficiency.

Axially Chiral Bis(α-amino Acid)s and Their Deamino Analogues. Synthesis and Configurational Assignment

1998 ◽  
Vol 63 (2) ◽  
pp. 211-221 ◽  
Author(s):  
Miloš Tichý ◽  
Luděk Ridvan ◽  
Miloš Buděšínský ◽  
Jiří Závada ◽  
Jaroslav Podlaha ◽  
...  
Keyword(s):  
Amino Acid ◽  
Nmr Spectra ◽  
Building Blocks ◽  
X Ray Diffraction ◽  
Amino Groups ◽  
X Ray ◽  
Configurational Assignment ◽  
Symmetry Properties ◽  
Axially Chiral ◽  
Polymeric Structures

The axially chiral bis(α-amino acid)s cis-2 and trans-2 as possible building blocks for polymeric structures of novel type of helicity were prepared. Their configuration has been determined by NMR spectroscopy and, in the case of the trans-isomer, confirmed by single-crystal X-ray diffraction. Analogous pair of stereoisomeric diacids cis-3 and trans-3, devoid of the amino groups, was also prepared and their configuration assigned. The observed differences in the NMR spectra of cis- and trans-isomers of 2 and 3 are discussed from the viewpoint of their different symmetry properties.

Synthesis of the six isomeric thieno[c]-fused 1,5- and 1,6-naphthyridines

1991 ◽  
Vol 56 (11) ◽  
pp. 2340-2351 ◽  
Author(s):  
Salo Gronowitz ◽  
Johan Malm ◽  
Anna-Britta Hörnfeldt
Keyword(s):  
Nmr Spectra ◽  
Coupling Reaction ◽  
One Pot ◽  
C Nmr

trough the use of Pd(0)-catalyzed coupling between 2- and 4-formyl-3-thiopheneboronic acids and 3-amino-2-bromopyridine and 4-acetamido-3-bromopyridine, convenient one-pot procedures for the preparation of thieno[2,3-c]-1,5-naphthyridine, thieno[3,4-c]-1,5-naphthyridine, thieno-[2,3-c]-1,6-naphthyridine, and thieno[3,4-c]-1,6-naphthyridine have been developed. In order to obtain thieno[3,2-c]-1,6-naphthyridine 2-(tributylstannyl)-3-thiophene aldehyde had to be used, since the organometallic partner in the coupling reaction, 3-formyl-2-thipheneboronic acid, is too easily deboronated. The effect of silver(I) oxide and thallium(I) carbonate on the coupling was studied. 1H and 13C NMR spectra of the six isomeric thieno{c]-fused 1,5- and 1,6-naphthyridines are discussed.

Purification of Penicillin Amidohydrolase, an Enzyme for Semisynthetic Procedures

1992 ◽  
Vol 57 (10) ◽  
pp. 2187-2191 ◽  
Author(s):  
Jiří Jiráček ◽  
Tomislav Barth ◽  
Jiří Velek ◽  
Ivo Bláha ◽  
Jan Pospíšek ◽  
...  
Keyword(s):  
Affinity Chromatography ◽  
Amino Groups ◽  
Primary Amino

Penicillin amidohydrolase (EC 3.5.1.11.) is one of the few enzymes used successfully for deprotection of primary amino groups of semisynthetic peptides. The available material is usually contamined by endo- and exopeptidases. We managed to prepare the enzyme devoid of trypsin- and chymotrypsin-like activities using affinity chromatography with specific ligands: Gly-D-Phe-Phe-Tyr-Thr-Pro-Lys-Thr (the fF peptide) and Leu-Gly-Val-D-Arg-Arg-Gly-Phe (the rR peptide). For further purification of the enzyme affinity chromatography with N-phenylacetyl-D-tert-Leu as a ligand was used.

Synthesis of Pyrrolo[1,2-a][1,6]- and [1,8]naphthyridines by Alkyne-Carbonyl Metathesis

Synthesis ◽  
2020 ◽  
Author(s):  
Peter Ehlers ◽  
Peter Langer ◽  
Marian Blanco Ponce ◽  
Silvio Parpart ◽  
Alexander Villinger ◽  
...  
Keyword(s):  
Heterocyclic Compounds ◽  
Metathesis Reaction ◽  
Synthetic Methodology ◽  
Facile Synthesis ◽  
Reaction Conditions ◽  
One Pot ◽  
Metal Free ◽  
Modular Synthesis

AbstractA concise and modular synthesis of pyrrolo[1,2-a][1,6]- and [1,8]naphthyridines by a one-pot two-step reaction consisting of electrophilic acylation followed by an alkyne-carbonyl-metathesis reaction as the final cyclization step is reported. This developed synthetic methodology allows the facile synthesis of these heterocyclic core structures in mainly high overall yields under metal-free conditions. Reaction conditions are carefully optimized and display a novel supplement to access these tricyclic heterocyclic compounds.

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