83432-87-5Relevant academic research and scientific papers
One dimensional unichemo protection (UCP) in organic synthesis
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, (2015/04/15)
A protected template molecule and a new one-dimensional UniChemo Protection (UCP) organic synthetic method for preparing polyfunctional organic molecules is described. The synthetic method can be used with many kinds of chemical reactions and provides selective access to many functional groups in a template molecule. The method utilizes protection groups that are each composed of building block units that can be removed one by one affording a new protection group one unit shorter or exposing a functional group on the template molecule. The exposed functional group on the template molecule can react with a target group. Different target groups can be introduced into the template molecule by using protection groups containing different numbers of building block units.
Conformational Behaviour of Medium-sized Rings. Part 11. Dianthranilides and Trianthranilides
Hoorfar, Alireza,Ollis, W. David,Price, Jennifer A.,Stephanatou, Julia Stephanidou,Stoddart, J. Fraser
, p. 1649 - 1700 (2007/10/02)
Two approaches to the stepwise syntheses of N,N'-di- and N,N',N''-tri-substituted trianthranilide derivatives (5)-(20) are described.In the shorter synthetic route, the key acyclic intermediate, N-anthranilic acid (26) is prepared in a stepwise manner from anthranilic acid, isatoic anhydride (23), followed by o-nitrobenzoyl chloride.Alkylations of the amide functions at nitrogen, reductions of the aromatic nitrogroups, and cyclisations of the acyclic amino-acid derivatives provide a direct route to N,N'-dimethyl- (5) and N,N'-dibenzyl- (14) trianthranilides.Further alkylations or acylations of either (5) or (14) afford (i) N,N',N''-trimethyltrianthranilide (7) and its trideuteriomethyl analogue (8), (ii) N,N'-dimethyl-N''-acetyl- (10), -N''-benzoyl- (11), and -N''-benzyl- (12) trianthranilides, (iii) N,N',N''-tribenzyltrianthranilide (15), and (iv) N,N'-dibenzyl-N''-methyltrianthranilide (16).In the longer synthetic route, the key acyclic intermediate, methyl N-methyl-N-anthranilate (42) is prepared in a stepwise manner from anthranilic acid and two molar equivalents of o-nitrobenzoyl chloride.Alkylations of the unsubstituted amide functions at nitrogen, reductions of the aromatic nitro-groups, and cyclisations of the acyclic amino-acid derivatives provide, not only an alternative route to N,N'-dimethyltrianthranilide (5) but also, a general route to the N-methyl-N'-trideuteriomethyl- (6), N-methyl-N'-benzyl- (17), and N-methyl-N'-ethyl- (19) analogues.Further alkylations of these N,N'-disubstituted derivatives afford N-methyl-N',N''-di(trideuteriomethyl)- (9), N-methyl-N'-trideuteriomethyl-N''-benzyl- (13), N-methyl-N'-benzyl-N''-ethyl- (18), and N-methyl-N'-ethyl-N''-benzyl- (20) trianthranilides.The constitutionally symmetrical N,N',N''-trimethyl- (7) and N,N',N''-tribenzyl- (15) trianthranilides exist in solution as an equilibrium mixture of propeller and helical conformations.In the case of the N,N',N''-trimethyl derivative (7), the predominant diastereoisomer with the helical conformation has been isolated as a pure compound.In the case of the N,N',N''-tribenzyl derivative (15), the propeller and helical conformational diastereoisomers have both been characterised as crystalline compounds.For both these compounds, the free-energy barriers to conformational inversion and interconversion processes in solution have been obtained from (i) direct equilibration experiments and (ii) dynamic 1H n.m.r. spectroscopy.Constitutionally unsymmetrical N,N'-di- and N,N',N''-tri-substituted trianthranilide derivatives can adopt three helical conformations in addition to a propeller conformation.Assignments have been made to conformations and conformational diastereoisomers of the N,N'-dimethyl- (5), N,N'-dimethyl-N''-benzyl- (12), N,N'-dibenzyl- (14), N,N'-dibenzyl-N''-methyl- (16), N-methyl-N'-benzyl- (17), N-methyl-N'-benzyl-N''-ethyl- ...
