Triphosgene, a Crystalline Phosgene Substitute

Eckert, H.; Forster, Barbara

doi:10.1002/anie.198708941

Cited by 377 publications

(167 citation statements)

References 9 publications

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“…1. Glu(OBzl)-NCA was prepared from triphosgene and the corresponding amino acid according to the method described in the literature [32,33], mp 89.7-90.0 • C. The structure was confirmed by 1 H NMR. The polymer PSf-E 5.8 was obtained by polymerization of 1.10 g of Glu(OBzl)-NCA solution in 30 cm 3 of chloroform with 0.66 g of PSf as the initiator.…”

Section: Preparation Of Polysulfone With Oligopeptide Side Chain (Psfmentioning

confidence: 99%

Evaluation of the recognition ability of molecularly imprinted materials by surface plasmon resonance (SPR) spectroscopy

Taniwaki

Hyakutake

Aoki

et al. 2003

Analytica Chimica Acta

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Polysulfone with an oligopeptide derivative of glutamyl residues (PSf-E 5.8 ) was evaluated as a candidate material for molecular recognition. PSf-E 5.8 was prepared from the N-carboxyanhydride of ␥-benzyl-l-glutamate (Glu(OBzl)-NCA) initiated by aminomethylated polysulfone (PSf). Films with molecular recognition sites with preference to adenosine (As) were prepared from PSf-E 5.8 by an alternative molecular imprinting method using 9-ethyladenine (9-EA) as a print molecule. The molecular recognition phenomena were studied by surface plasmon resonance (SPR) spectroscopy. The apparent affinity constant of the molecular recognition sites toward As was dependent on the imprinting condition and was increased from 1.30 × 10 4 to 1.60 × 10 4 mol −1 dm 3 with the decrease in the molecular imprinting ratio from 1.0 to 0.25. From the present study, it was shown that SPR is a convenient and facile method to detect molecular recognition interactions.

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Section: Preparation Of Polysulfone With Oligopeptide Side Chain (Psfmentioning

confidence: 99%

Evaluation of the recognition ability of molecularly imprinted materials by surface plasmon resonance (SPR) spectroscopy

Taniwaki

Hyakutake

Aoki

et al. 2003

Analytica Chimica Acta

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“…The Esc group was introduced onto amino acids by the reaction of 2-ethanesulfonylethyl chloroformate (Esc-Cl) as shown in Chart 1 (Route 1). 2-Ethanesulfonylethanol was converted to Esc-Cl by treatment with phosgene (prepared from triphosgene) 7) in dichloromethane. Since Esc-Cl was labile and decomposed during purification, it was used without purification for the next acylating reaction.…”

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confidence: 99%

Peptide Synthesis in Water IV. Preparation of N-Ethanesulfonylethoxycarbonyl (Esc) Amino Acids and Their Application to Solid Phase Peptide Synthesis

Hojo

Maeda

Smith

et al. 2004

CHEMICAL & PHARMACEUTICAL BULLETIN

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Synthesis of peptides was an arduous task before development of the solid phase method. The solid phase method has facilitated automated peptide synthesis and the development of combinatorial chemistry. It has many advantages compared with classical solution peptide synthesis, but requires a large amount of organic solvents. Disposal of organic solvents is one of many important environmental problems, therefore we decided to perform peptide synthesis in water. To perform synthesis in water, protected amino acids must be water-soluble. We have studied water-soluble N-protecting groups and we developed 2-[phenyl(methyl)sulfonio]ethoxycarbonyl (Pms) 1,2) as a water-soluble N-protecting group. Since the Pms group is an onium salt, it is rather unstable in comparison with N-protecting groups which are in general use (such as t-butoxycarbonyl group, 3) benzyloxycarbonyl group 4) and 9-fluorenylmethoxycarbonyl (Fmoc) group 5) ) for peptide synthesis. Here we report preparation of the ethanesufonylethoxycarbonyl (Esc) group and its application to peptide synthesis in water.Tesser and Balvert-Geers 6) reported the methanesulfonylethoxycarbonyl (Msc) group as a readily removable Nprotecting group by treatment with 0.1 or 0.2 N NaOH solution. This protecting group is hydrophilic rather than hydrophobic. We designed the Esc group (Fig. 1), expecting it to display both hydrophilic and hydrophobic character (i.e. we expect Esc-amino acids to exhibit reasonable solubility in aqueous and organic solvents). The Esc group was introduced onto amino acids by the reaction of 2-ethanesulfonylethyl chloroformate (Esc-Cl) as shown in Chart 1 (Route 1). 2-Ethanesulfonylethanol was converted to Esc-Cl by treatment with phosgene (prepared from triphosgene) 7) in dichloromethane. Since Esc-Cl was labile and decomposed during purification, it was used without purification for the next acylating reaction. Esc-Cl, H-Phe-OH and triethylamine were allowed to react in aqueous 50% acetonitrile to give Esc-Phe-OH. HPLC analysis of the crude product exhibited impurities and the product could not be purified by silica gel column chromatography and recrystallization. Pure Esc-Phe-OH was obtained by RP-HPLC purification and the yield was 38%. To improve the reaction yield and purification procedure, another synthetic route (Route 2 in Chart 1) to the Escamino acid was studied. 2-Ethanesulfonylethanol was reacted with 4-nitrophenyl chloroformate to give ethanesulfonylethyl-4-nitrophenyl carbonate (Esc-ONp). The crude EscONp was stable and could be purified by silica gel column chromatography or recrystallization from a mixture of ether and hexane. The yield was 78%. Other Esc-amino acids (Esc-Leu-OH, Esc-Gly-OH, Esc-Tyr-OH) were also prepared using Esc-ONp and their analytical data are shown in Table 1. Esc-Gly-OH and Esc-Tyr-OH were soluble in water and Esc-Leu-OH and Esc-Phe-OH were not readily soluble in water. Esc-Leu-OH and Esc-Phe-OH were soluble in aqueous 2% Triton X. To evaluate Esc-amino acids, Leu-enkephalin amide was synthesized by the sol...

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“…Substituted phenyl isocyanate (1) was obtained from substituted aniline by refluxing with bis(trichloromethyl) carbonate (BTC) in dry ethyl acetate. A solution of isocyanate 1 in acetone was added dropwise to a solution of ammonia in the same solvent at 0-5 o C afforded substituted phenylurea (2) [7][8]. Subsequent treatment of compound 2 with cyanoacetic acid furnished N-(2-cyanoacetyl)-N'-(substituted phenyl)urea (3) [9], N- (2-cyano-3,3-dimethylthioacrylyl)-N'-(substituted phenl)urea (4) was obtained from compound 3 by reacting with KOH and carbon disulfide with dimethyl sulfide as methylation agent.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and crystal structure of N-(3-benzylamino-2- cyano-3-methylthioacrylyl)-N'-(substituted phenyl)ureas

Zhong¹,

Fan²,

Liu³

et al. 2013

Bull. Chem. Soc. Eth.

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Triphosgene, a Crystalline Phosgene Substitute

Cited by 377 publications

References 9 publications

Evaluation of the recognition ability of molecularly imprinted materials by surface plasmon resonance (SPR) spectroscopy

Evaluation of the recognition ability of molecularly imprinted materials by surface plasmon resonance (SPR) spectroscopy

Peptide Synthesis in Water IV. Preparation of N-Ethanesulfonylethoxycarbonyl (Esc) Amino Acids and Their Application to Solid Phase Peptide Synthesis

Synthesis and crystal structure of N-(3-benzylamino-2- cyano-3-methylthioacrylyl)-N'-(substituted phenyl)ureas

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