Valeric amide

Valer amide Lactic acid di ethyl CIWCHahCONHa 15 0.769 0.241 0.313... 

Albericio F, Kneib-Cordonier N, Biancalana S, Gera L, Masada RI, Hudson D, Barany G. Preparation and application of the 5-(4-(9-fluorenylmethoxycarbonyl)aminomethyl-3, 5-dimethoxyphenoxy)-valeric acid (PAL) handle for the solid-phase synthesis of C-terminal peptide amides under mild conditions. J Org Chem 1990 55 3730-3743. 

Amine-reactive biotinylation reagents contain reactive groups off biotin s valeric acid side chain that are able to form covalent bonds with primary amines in proteins and other molecules. Two basic types are commonly available N-hydroxysuccinimide (NHS) esters and carboxylates. NHS esters spontaneously react with amines to form amide linkages (Chapter 2, Section 1.4),... 

The Derivative, 5-(biotinamido)pentylamine, contains a 5-carbon cadaverine spacer group attached to the valeric acid side chain of biotin (Thermo Fisher). The compound can be used in a carbodi-imide reaction process to label carboxylate groups in proteins and other molecules, forming amide bond linkages (Chapter 3, Section 1). However, the main use of this biotinylation reagent is in the determination of factor XHIa or transglutaminase enzymes in plasma, cell, or tissue extracts. 

Later investigators alcoholyzed imidate salts of other monobasic acids to obtain ortho esters of acetic [13, 14], propionic [15], butyric, valeric, caproic, isocaproic, benzoic [16], and phenylacetic acids [17]. For the latter alcoholysis reactions, the reaction time varies from a few days for the production of methyl orthopropionate to six weeks for ethyl orthobenzoate. McElvain reported that the reaction time is drastically cut by carrying out the reaction in boiling ether [18] or petroleum ether [19]. These conditions provide a reaction temperature below the decomposition point of the imidate salt to the amide. 

There are a number of reports in the literature on the photochemistry of amides, including the photodegradation of serum albumin,224 and of polypeptides.1 Photodegradation involves reactions of acyl and imine free radicals generated by photolytic scission of the amide group.23 33 The photooxidation of N-pentylhexanamide led to the formation of n-valeraldehyde and valeric acid from the amine part of the molecule... 

Albericio, F. Kneib-Cordonier, N. Biancalana, S. Gera, L. Masada, R. I. Hudson, D. Barany, G. Preparation and Application of the 5-(4-(9-Fluo-renylmethyloxycarbonyl)aminomethyl-3,5-dimethoxyphenoxy)-valeric Acid (PAL) Handle for the Solid-Phase Synthesis of C-Terminal Peptide Amides under Mild Conditions, J. Org. Chem. 1990, 55, 3730. 

Azido-iso-voleric Acid Amide. See under Valeric Acid Amide and Beil 2, 318... 

There are two possibilities for the preparation of protected peptide amides the 5-[(9- [(9//-fluoren-9-ylmethoxy)carbonyl]amino -9//-xanthen-3-yl)oxy]valeric acid (XAL handle, and its precursor XAL resin 27 provides Fmoc/tBu-protected peptide amides by treatment with low concentrations of TFA ( 1%), and the 3-nitro-4-aminomethylbenzyl handles 28, which are photolabile handles and are compatible with both Boc/Bzl and Fmoc/ tBu strategies. 

Abbreviations used Dde, N-[l-(4,4-dimethyl-2,6-dioxocyclohexadiene)]-ethyl DIEA, diisopropylethylamine DMF, N,N-dimethylformamide EDC, l-Ethyl-3-(3 -dimethylaminopropyl)carbodiimide hydrochloride HOBt, 1-hydroxybenzotriazole NHS, N-hydroxysuccinimide NMP, l-methyl-2-pyrroIidinone PAL, Peptide Amide Linker [5-(4-(9-fluorenylmethyloxycarbonyl) aminomethyl-3,5-dimethoxyphenoxy) valeric acid] PyBOP, Benzotriazole-l-yl-oxy-trispyrrolidino-phosphonium hexafluorophosphate TFA, trifluoroacetic acid. 

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