Resolutions and an Attempted Partial Asymmetric Synthesis in Papain-Catalyzed Syntheses of N^α,N^β-Diacylhydrazines from Hydrazides and Acylated Amino Acids

Abstract

N",N0-Diacylhydrazities have been prepared successfully from hydrazides and acylated amino acids by papain catalysis. In every reaction where racemic acylated amino acids were employed, resolution occurred. The optimum pH for the reaction between benzhydrazide and hippuric acid ivas about 4. Twenty-six new diacylhydrazines were prepared. In the reaction between DL-mandelic hydrazide and hippuric acid no resolution occurred, but a racemic product resulted. An attempted partial asymmetric synthesis in the reaction between ethylmalonic hydrazide and carbobenzoxyglycine was not successful, but this reaction likewise gave a racemic product.

Ficin as a catalyst in organic syntheses

“…Ficin contains a mercapto group, -SH, at its active site, which in part explains its similarity in catalytic behavior to papain from green papaya fruit, bromelin from pineapple juice, and bromelain from stalks of mature pineapple plants. Undoubtedly, the variety of synthetic reactions catalyzed by ficin will prove to be as great as when papain is employed as the enzyme (2). A few extensions of fichi-catalyzed syntheses have been those between benzenesulfonhydrazide (3) and the familiar soluble, acylated amino acids: hippuric acid, carbobenzoxyglycine, carbobenzoxy-L-alanine, and carbobenzoxy-DL-alanine.…”

Papain as an enzyme catalyst in undergraduate organic chemistry

“…Another such series of combinations would be the reactions between amido acids like hippuric acid and benzhydrazide or other hydrazides (10) to yield Na, Nediacylhydrazines.…”

Robust preparation of novel imidazo[5,1-b][1,3,4]oxadiazoles

“…Hence, conversion of CBz-protected glycine 4 to the benzoyl hydrazide 5 7,8 using EDCI was followed by deblocking of the carbamate and a second peptide coupling with benzoic acid to furnish the requisite acyl hydrazide 2a. 9 Boc protection of the amino acid subunit was similarly successful for obtaining acyl hydrazides 2, obviating the need for hydrogenation (see ESI †).…”