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10061 Amino-dPEG 6-t-butyl ester

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CAS: 1286281-32-0

Item Name: Amino-dPEG 6-t-butyl ester

Item #: 10061

Mol. Wt.: 409.51;

single compound dPEG Spacer is 22 atoms and 25.1 A

10061 Amino-dPEG 6-t-butyl ester

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$135.00

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CAS: 1286281-32-0
Item Name: Amino-dPEG 6-t-butyl ester
Item #: 10061
Mol. Wt.: 409.51;
single compound dPEG Spacer is 22 atoms and 25.1 A
Product Features and Benefits: A carboxy protected dPEG x amino acid pegylation reagent dPEG pegylation spacer and modifier with a reactive amine and a t-butyl protected carboxylic acid. dPEG pegylation spacer is extremely hydrophilic, will enhance the water solubility of a compound in which it is incorporated and reduce non-specific binding where applicable. The spacer is also non-immunogenic. The ester is both water soluble, as well as in common used organic solvents of moderate prolarity. t-Butyl group is easily removed with TFA (25% TFA in CH2Cl2, ice bath/0oC, takes about 5 h) t-Butyl group provides a potentially powerful purification handle due to its hydrophobicity. Subsequently it is removed to perform additional chemistry. This applies best when using normal phase (e.g., silica gel) chromatography. t-Butyl group neutralizes the zwitterion of the amino acid for better reactivity at the amine Reacts with carboxylic acids and other carbonyls Protocols: The following are general use guidelines for reaction with: a. Reaction with an active ester: Find a solvent in which active ester is soluble (methylene chloride is a preferred solvent) and dissolve the ester in the dry solvent, add triethylamine, then add the amine, either neat or drop wise as a solution in the reaction solvent. Use at least a 10% excess of all reagents relative to the active ester. This can be carried out at ambient temperatures. b. Reaction with a free acid: generate the active ester in situ with EDC and NHS or HOBt, then add the triethylamine, followed by the amino-dPEG 4 t-butyl ester; or ii) combine the acid, NHS or HOBt, TEA, and the amino-dPEG 4 t-butyl ester, and add a solution of the EDC. Use at least a 10% excess of reagents relative to the acid. Note: Carbodiimides other than EDC can be used, but the water soluble and polar nature of the by-products makes work-up very efficient with EDC. DCC is also very good, if one is able to remove all of the DCU. These reactions are best carried out at 10-0oC. The reactions all need to be monitored by chromatography, TLC, or HPLC.