81084-79-9

Upstream product

• 67-63-0 isopropyl alcohol 
• 609-36-9 rac-Pro-OH 
• 634-97-9 pyrrole-2-carboxyl acid 
• 35889-88-4 propan-2-yl 1H-pyrrole-2-carboxylate 
• 97466-19-8 (S)-pyrrolidine-2-carboxylic acid isopropyl ester hydrochloride 
• 147-85-3 L-proline 

Relevant academic research and scientific papers

Characterization and cytotoxicity evaluation of biocompatible amino acid esters used to convert salicylic acid into ionic liquids

The technological utility of active pharmaceutical ingredients (APIs) is greatly enhanced when they are transformed into ionic liquids (ILs). API-ILs have better solubility, thermal stability, and the efficacy in topical delivery than solid or crystalline drugs. However, toxicological issue of API-ILs is the main challenge for their application in drug delivery. To address this issue, 11 amino acid esters (AAEs) were synthesized and investigated as biocompatible counter cations for the poorly water-soluble drug salicylic acid (Sal) to form Sal-ILs. The AAEs were characterized using 1H and 13C NMR, FTIR, elemental, and thermogravimetric analyses. The cytotoxicities of the AAE cations, Sal-ILs, and free Sal were investigated using mammalian cell lines (L929 and HeLa). The toxicities of the AAE cations greatly increased with inclusion of long alkyl chains, sulfur, and aromatic rings in the side groups of the cations. Ethyl esters of alanine, aspartic acid, and proline were selected as a low cytotoxic AAE. The cytotoxicities of the Sal-ILs drastically increased compared with the AAEs on incorporation of Sal into the cations, and were comparable to that of free Sal. Interestingly, the water miscibilities of the Sal-ILs were higher than that of free Sal, and the Sal-ILs were miscible with water at any ratio. A skin permeation study showed that the Sal-ILs penetrated through skin faster than the Sal sodium salt. These results suggest that AAEs could be used in biomedical applications to eliminate the use of traditional toxic solvents for transdermal delivery of poorly water-soluble drugs.

The reactions of α-amino acids and α-amino acid esters with high valent transition metal halides: synthesis of coordination complexes, activation processes and stabilization of α-ammonium acylchloride cations

Titanium tetrachloride smoothly reacted with a selection of α-amino acids (aaH) in CH2Cl2 affording yellow to orange solid coordination compounds, 1a-d, in 70-78% yields. The salts [NHEt3][TiCl4(aa)], 2a-b, were obtained from TiCl4/aaH/NEt3 (aa = l-phenylalanine, N,N-dimethylphenylalanine), in 60-65% yields. The complex , 3, was isolated from the reaction of l-proline with NbCl5/NHiPr2, performed in CH2Cl2 at room temperature. The X-ray structure of 3 features a bridging (E)-1,2-bis(3,4-dihydro-2H-pyrrol-5-yl)ethene-1,2-diolate ligand, resulting from the unprecedented C-C coupling between two proline units. Unusually stable α-ammonium acyl chlorides were prepared by the reactions of PCl5/MCln (MCln = NbCl5, WCl6) with l-proline, N,N-dimethylphenylalanine, sarcosine and l-methionine. MX5 (M = Nb, Ta; X = F, Cl) reacted with l-leucine methylester and l-proline ethylester to give ionic coordination compounds, [MX4L2][MX6] (M = Nb, L = Me2CHCH2CH(NH2)CO2Me, X = F, 9; Cl, 11a; M = Nb, X = Cl, , 11c; Ta, 11d), in moderate to good yields. [NbCl5(Me2CHCH2CHNH3CO2Me)][NbCl6], 12, was isolated as a co-product of the reaction of NbCl5 with l-leucine isopropylester, and crystallographically characterized. The reaction of NbCl5 with l-serine isopropylester afforded NbCl3(OCH2CHNHCO2iPr), 13, in 66% yield. The activation of the ester O-R bond was observed in the reactions of l-leucine methyl ester with NbF5 and l-proline ethyl ester with MBr5 (M = Nb, Ta), these reactions proceeding with the release of EtF and EtBr, respectively. All the metal products were characterized by analytical and spectroscopic methods, while DFT calculations were carried out in order to provide insight into the structural and mechanistic aspects.

NOVEL COMPOUND, PHOTOSENSITIVE RESIN COMPOSITION, AND COLOR FLITER

The present invention relates to a novel compound, a photosensitive resin composition comprising the compound and a color filter and, more specifically, to a compound represented by chemical formula 1, a photosensitive resin composition comprising the compound, an alkali-soluble resin, a photopolymerizable compound, a photopolymerization initiator and a solvent, and a color filter manufactured by using the photosensitive resin composition.COPYRIGHT KIPO 2016

Highly efficient proline ester-based nickel catalysts for Michael addition of thiophenols to α,β-enones

Two N3O2 pentadentate ligands, BMPP and BPPP, were prepared for synthesizing highly efficient nickel catalysts, [Ni(BMPP)(CH 3CN)](ClO4)2 (1) and [Ni(BPPP)(CH 3CN)](BPh4)(ClO4) (2), for thia-Michael addition of thiophenols to α,β-enones. X-ray structures of 1 and 2 revealed that a labile CH3CN molecule was bound to the nickel center of the catalysts. ESI-MS spectroscopy indicated that thiolate replaced the bound CH3CN molecule and coordinated to the nickel center during the catalytic cycle.

Comparison of liquid chromatography-isotope ratio mass spectrometry (LC/IRMS) and gas chromatography-combustion-isotope ratio mass spectrometry (GC/C/IRMS) for the determination of collagen amino acid δ13C values for palaeodietary and palaeoecological reconstruction

Results are presented of a comparison of the amino acid (AA) δ13C values obtained by gas chromatography-combustion-isotope ratio mass spectrometry (GC/C/IRMS) and liquid chromatography-isotope ratio mass spectrometry (LC/IRMS). Although the primary focus was the compound-specific stable carbon isotope analysis of bone collagen AAs, because of its growing application for palaeodietary and palaeoecological reconstruction, the results are relevant to any field where AA δ13C values are required. We compare LC/IRMS with the most up-to-date GC/C/IRMS method using N-acetyl methyl ester (NACME) AA derivatives. This comparison involves the analysis of standard AAs and hydrolysates of archaeological human bone collagen, which have been previously investigated as N-trifluoroacetyl isopropyl esters (TFA/IP). It was observed that, although GC/C/IRMS analyses required less sample, LC/IRMS permitted the analysis of a wider range of AAs, particularly those not amenable to GC analysis (e.g. arginine). Accordingly, reconstructed bulk δ13C values based on LC/IRMS-derived δ13C values were closer to the EA/IRMS-derived δ13C values than those based on GC/C/IRMS values. The analytical errors for LC/IRMS AA δ13C values were lower than GC/C/IRMS determinations. Inconsistencies in the δ13C values of the TFA/IP derivatives compared with the NACME- and LC/IRMS-derived δ13C values suggest inherent problems with the use of TFA/IP derivatives, resulting from: (i) inefficient sample combustion, and/or (ii) differences in the intra-molecular distribution of δ13C values between AAs, which are manifested by incomplete combustion. Close similarities between the NACME AA δ13C values and the LC/IRMS-derived δ13C values suggest that the TFA/IP derivatives should be abandoned for the natural abundance determinations of AA δ13C values.

Ryanoids and related compounds - Chemoselective electrocatalytic hydrogenation of alkyl α-pyrrole carboxylates: Selective hydrogenation of ryanodine

A study of the electrocatalytic hydrogenation (ECH) process of pyrrote and different alkyl pyrrole-2-carboxylates is presented. Once hydrogenated, the alkyl pyrrole-2-carboxylate becomes an ester of proline, an important natural amino acid. The process is chemoselective to the pyrrole ring. Ryanodine is a natural ryanoid known to be biologically active. The tetrahydroryanodine derivative thus obtained may now represent a molecule of high biological interest. The hydrogenation of ryanodine is possible with electrocatalytic and catalytic processes. In both cases the reaction is not diastereoselective.

Organonickel(II) complexes containing aryl ligands with chiral pyrrolidinyl ring systems; syntheses and use as homogeneous catalysts for the Kharasch addition reaction

New chiral organonickel(II) complexes 3a-d have been synthesized containing monoanionic terdentate ligands of the type 2,6-bisphenyl. 3a R1=Me(racemic), R2=H, 3b R1=Me(S), R2=H, 3c R1=Me(R), R2=Me(R), 3d R1=C(O)OPr-i(S), R2=H.Chirality is introduced at the nitrogen donor atoms, which are part of the pyrrolidinyl ring systems, by placing substituents on the 2 or 5 positions of the rings.The complexes have been characterized variously by 1H- and 13C-NMR spectroscopy, UV/Vis spectroscopy and X-ray crystallography.Crystals of 3b are monoclinic, space group P21, with a = 11.572(2), b = 11.804(2), c=13.249(3) Angstroem, β=107.00(2) deg, Z=4, final R=o.o43 for 3043 observed reflections.Crystals of 3c are tetragonal, space group P412121, with a = b = 12.2957(14) Angstroem, c = 26.418(3) Angstroem, Z = 8, final R = 0.052 for 1479 observed reflections.Crystals of 3d are tetragonal, space group P412121 with a = b = 11.0869(5), c = 21.718(2) Angstroem, Z = 4, final R = 0.046 for 1469 observed reflections.The catalytic ability of the nickel complexes in the addition reaction of polyhalogenated compounds with alkenes (Kharasch addition) is markedly influenced by the geometry around the nickel atom and only 3a and 3b prove to be effective catalysts.The highest enantiomeric excesses of 16-17percent obtained with 3b and L-menthyl methacrylate in this catalytic reaction indicate that the C2 chiral fence produced by the Me-substituted pyrrolidinyl rings is not very effective for the transfer of chiral information.