6533b850fe1ef96bd12a8630

RESEARCH PRODUCT

Susceptibility of Methyl 3-Amino-1H-pyrazole-5-carboxylate to Acylation

ŁUkasz. GóreckiBarbara RzeszotarskaAnna Kusakiewicz-dawidElzbieta Masiukiewicz

subject

chemistry.chemical_classificationmethyl 3-amino-1H-pyrazole-5-carboxylatearomatic amineCarboxylic acidOrganic ChemistryAromatic aminePyrazoletert-butyloxycarbonylationRing (chemistry)Combinatorial chemistryAcylationchemistry.chemical_compoundAcetic anhydridechemistryacylationOrganic chemistryImidazoleCarboxylate2-(2-methoxyethoxy)ethoxyacetylationacetylation

description

Abstract In the search for a new method of synthesis of hybrid peptides with aminopyrazole carboxylic acid, we tried to force selective acylation at the aromatic amino group instead of at the ring nitrogen atom with fairly gentle acylating agents. The acylating agents used were acid anhydrides: acetic anhydride, tert-butyl pyrocarbonate, and 2-(2-methoxyethoxy)ethoxyacetic acid/dicyclohexylcarbodiimide. We succceded in acylation at this amino group with almost none at the ring nitrogen atom. Sometimes, however, acylation in small quantities at the ring nitrogen atom was observed as a by-product. To remove this by-product, imidazole was used. Thus, we were able to obtain the hybrid peptides in question with no protection and subsequent removal required. We synthesized a few these free peptides with no protection of the pyrazole ring. This is a simpler method than that being used currently.

https://doi.org/10.1080/00397910902898536