Hydride Reductions of 1H-Pyrrolo[2,1-c][1,4]-benzodiazepine-5,11-diones: Selective Reduction of Secondary Amides to Carbinolamines

1998 ◽  
Vol 51 (12) ◽  
pp. 1121 ◽  
Author(s):  
Andrew G. Katsifis ◽  
Meredith E. McPhee ◽  
Damon D. Ridley

For the syntheses of radiolabelled pyrrolo[1,4]benzodiazepine antitumour antibiotics we required a method in which the unstable carbinolamine functionality was introduced prior to the radiolabel. In turn this required the selective reduction of a secondary amide in the presence of, inter alia, a tertiary amide. We report methods which can be used to achieve this outcome in a series of 1H-pyrrolo[2,1-c][1,4]benzodiazepine-5,11-diones.

Separations ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 139
Author(s):  
Yuki Ueda ◽  
Shintaro Morisada ◽  
Hidetaka Kawakita ◽  
Keisuke Ohto

The recycling of rare metals such as platinum (Pt) from secondary resources, such as waste electronic and electrical equipment and automotive catalysts, is an urgent global issue. In this study, simple secondary amides and urea, N-(2-ethylhexyl)acetamide, N-(2-ethylhexyl)octanamide, and 1-butyl-3-(2-ethylhexyl)urea, which selectively extract Pt(IV) from a simulated effluent containing numerous metal ions, such as in an actual hydrometallurgical process, were synthesized and achieved efficient Pt(IV) stripping using only water. Comparison of Pt(IV) extraction behavior with a tertiary amide without N–H moieties suggests that the secondary amides and urea extractants effectively use hydrogen bonding to the hexachloroplatinate anion by N–H moieties. Examining the conditions for the third phase formation revealed that the secondary amide extractant with the longest alkyl chain can be used in the extraction process for a long time without forming any third phase, despite its lower Pt(IV) extraction capacity. The practical trial with simple compounds developed in this study should contribute to the development of Pt separation and purification processes.


2008 ◽  
Vol 8 (5) ◽  
pp. 1181-1194 ◽  
Author(s):  
J. Zahardis ◽  
S. Geddes ◽  
G. A. Petrucci

Abstract. The oxidative processing by ozone of the particulate amines octadecylamine (ODA) and hexadecylamine (HDA) is reported. Ozonolysis of these amines resulted in strong NO2– and NO3– ion signals that increased with ozone exposure as monitored by photoelectron resonance capture ionization aerosol mass spectrometry. These products suggest a mechanism of progressive oxidation of the particulate amines to nitroalkanes. Additionally, a strong ion signal at 125 m/z is assigned to the ion NO3– (HNO3). For ozonized mixed particles containing ODA or HDA + oleic acid (OL), with pO3≥3×10–7 atm, imine, secondary amide, and tertiary amide products were measured. These products most likely arise from reactions of amines with aldehydes (for imines) and stabilized Criegee intermediates (SCI) or secondary ozonides (for amides) from the fatty acid. The routes to amides via SCI and/or secondary ozonides were shown to be more important than comparable amide forming reactions between amines and organic acids, using azelaic acid as a test compound. Finally, direct evidence is provided for the formation of a surface barrier in the ODA + OL reaction system that resulted in the retention of OL at high ozone exposures (up to 10−3 atm for 17 s). This effect was not observed in HDA + OL or single component OL particles, suggesting that it may be a species-specific surfactant effect from an in situ generated amide or imine. Implications to tropospheric chemistry, including particle bound amines as sources of oxidized gas phase nitrogen species (e.g.~NO2, NO3), formation of nitrogen enriched HULIS via ozonolysis of amines and source apportionment are discussed.


2020 ◽  
Author(s):  
Tatiana Rogova ◽  
Pablo Gabriel ◽  
Stamatia Zavitsanou ◽  
Jamie Leitch ◽  
Fernanda Duarte ◽  
...  

A new strategy for the mild generation of synthetically valuable α-amino radicals from robust tertiary amide building blocks has been developed. By combining Vaska’s complex-catalyzed tertiary amide reductive activation and photochemical single electron reduction into a streamlined tandem process, metastable hemiaminal intermediates were successfully transformed into nucleophilic α-amino free radical species. This umpolung approach to such reactive intermediates was exemplified through coupling with an electrophilic dehydroalanine acceptor, resulting in the synthesis of an array of α-functionalized tertiary amine derivatives, previously inaccessible from the amide starting materials. The utility of the strategy was expanded to include secondary amide substrates, intramolecular variants and late stage functionalization of an active pharmaceutical ingredient. DFT analyses were used to establish the reaction mechanism and elements of the chemical system that were responsible for the reaction’s efficiency.


2017 ◽  
Vol 24 (2) ◽  
pp. 61-69 ◽  
Author(s):  
Tsuyoshi SUGITA ◽  
Iori FUJIWARA ◽  
Hiroyuki OKAMURA ◽  
Tatsuya OSHIMA ◽  
Yoshinari BABA ◽  
...  

1978 ◽  
Vol 45 (1) ◽  
pp. 85-92 ◽  
Author(s):  
J. G. Zadow ◽  
R. D. Hill

SummaryThe precipitation of proteins from whey by modified carboxymethyl cellulose (CMC) was examined. Carboxymethyl cellulose containing acetyl, methoxyl or carboxymethyl secondary amides with iso-propyl, n-propyl, iso-butyl, n-butyl or cyclohexyl side chains precipitated more protein than did CMC of similar carboxyl content. This effect was greatest in CMC containing secondary amide groups. The increase in protein precipitation gained by introduction of secondary amide groups into CMC was no greater however than the increase obtained by introduction of a similar number of carboxymethyl groups into the polymer. Carboxyethyl cellulose did not form insoluble complexes with whey proteins under the conditions examined.


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