Kinetic Analysis and Mechanism of the Hydrolytic Degradation of Squaramides and Squaramic Acids

M Ximenis, E Bustelo, AG Algarra, M Vega… - The Journal of …, 2017 - ACS Publications
The hydrolytic degradation of squaramides and squaramic acids, the product of partial
hydrolysis of squaramides, has been evaluated by UV spectroscopy at 37° C in the pH …

The nucleophilic substitution reactions in s-triazanic systems—I: Kinetics and mechanism of alkaline hydrolysis of the melamine

G Ostrogovich, R Bacaloglu, E Fliegl - Tetrahedron, 1968 - Elsevier
It was established through kinetic determinations that the alkaline hydrolysis of melamine is
an SNAr2 mechanism scheme. The two process steps have near reaction rates, but as each …

Hydrocarbon analog of the squarate dianion. Evidence for its possible aromaticity and the examination of its behavior with two quenching agents

WT Thorstad, NS Mills, DQ Buckelew… - The Journal of Organic …, 1989 - ACS Publications
The hydrocarbon analogue of the squarate dianion 2 was prepared by metalating l, 2-
dimethyl-3, 4-bis-methylenecyclobutene with n-butyllithium/potassium tert-butoxide or n …

Squaramide equilibrium acidities in DMSO

X Ni, X Li, Z Wang, JP Cheng - Organic letters, 2014 - ACS Publications
A number of popular squaramide organocatalysts' acidities were determined by an
overlapping indicator method in DMSO via UV spectrophotometric titrations. The p K a …

Alkaline hydrolysis of N-methylazetidin-2-one. Hydration effects

J Frau, J Donoso, F Munoz, B Vilanova… - Journal of Molecular …, 1998 - Elsevier
Semiempirical calculations (PM3) have been used to investigate the reaction mechanism
(BAC2) of the alkaline hydrolysis of N-methylazetidin-2-one. This mechanism involves the …

Theoretical study on the alkaline and neutral hydrolysis of succinimide derivatives in deamidation reactions

FA Konuklar, V Aviyente… - The Journal of Physical …, 2002 - ACS Publications
The hydrolysis of a succinimide derivative in alkali and neutral media has been studied at
the B3LYP/6-31+ G* level. Stepwise and concerted mechanisms have been considered in a …

Squaramides: physical properties, synthesis and applications

RI Storer, C Aciro, LH Jones - Chemical Society Reviews, 2011 - pubs.rsc.org
Squaramides are remarkable four-membered ring systems derived from squaric acid that
are able to form up to four hydrogen bonds. A high affinity for hydrogen bonding is driven …

Squaric acid diethylester: a simple and convenient coupling reagent

KH Glüsenkamp, W Drosdziok, G Eberle… - … für Naturforschung C, 1991 - degruyter.com
A new method for the covalent modification of polymers in a two-step process is described.
Squaric acid diethylester reacts with primary or secondary aliphatic amines selectively to …

An efficient general synthesis of squarate esters

H Liu, CS Tomooka, HW Moore - Synthetic communications, 1997 - Taylor & Francis
An efficient and general method for the synthesis of alkyl squarates is presented. This
involves the reactions of squaric acid with the desired alcohol in the presence of an …

The regioselectivity and synthetic mechanism of 1, 2-benzimidazole squaraines: combined experimental and theoretical studies

G Xia, Z Wu, Y Yuan, H Wang - RSC advances, 2013 - pubs.rsc.org
In this paper, a synthetic method to produce 1, 2-benzimidazole squaraines with a yield of
up to 89% is developed. It is found that both strong organic and inorganic bases have a …