- An efficient synthesis of N,N,N′,N′,N″-pentamethyldipropylenetriamine
-
N,N,N′,N′,N″-Pentamethyldipropylenetriamine (PMDPTA) has for a long time been employed as an efficient catalyst in the production of polyurethane materials. A green and effective synthetic route to PMDPTA was successfully established from experiments described in this paper. PMDPTA was obtained from methylamine, acrylonitrile and formaldehyde via a Michael addition, catalytic hydrogenation and methylation in 65% overall yield. Furthermore, methanol was employed as the only solvent in all of the three steps, resulting in the convenient recovery of methanol. This route is thus suitable for industrial production.
- Gui, Sizhe,Mu, Manman,Luo, Hao,Liu, Na,Shen, Huawei,Chen, Ligong
-
p. 486 - 488
(2016/08/13)
-
- Anxiolytic properties of certain annelated [1,2,3]triazolo[1,5-c]pyrimidin-5(6H)-ones
-
Modification of the benzodiazepine (BZ) receptor binding template 2-aryl[1,2,4]triazolo[1,5-c]quinazolin-5(6H)-one by replacement of the annelated benzene ring with various alicyclic and heterocyclic moieties led to novel structures with potent BZ receptor binding affinity. High affinity was found in some cycloalkyl-annelated [1,2,4]triazolo[1,5-c]pyrimidin-5(6H)-ones and in some 7,8,9,10-tetrahydropyrido[3,4-e][1,2,4]triazolo[1,5-c] pyrimidin-5(6H)-ones, in which the degree of activity was strongly dependent on the N-substituent in the 9-position. Nine compounds with BZ receptor IC50 binding affinity values equal or superior to diazepam were evaluated in secondary screening. One of these, 9-benzyl-2-phenyl-7,8,9,10-tetrahydropyrido[3,4-e] [1,2,4]triazolo[1,5-c]pyrimidin-5(6H)-one, showed good activity in rats as a potential anxiolytic agent without sedative liability. However, it increased the rotorod deficit produced by ethanol at anxiolytic doses, an indication of alcohol interaction. Thus, none of the compounds showed an advantage over CGS 9896 (Yokoyama et al. J. Med. Chem. 1982, 25, 337-339), which is free of sedative and alcohol interaction potential as measured by the test procedures described.
- Francis,Bennett,Hyun,Rovinski,Amrick,Loo,Murphy,Neale,Wilson
-
p. 2899 - 2906
(2007/10/02)
-
- Chemistry of Nitrogen Mustard studied by Nuclear Magnetic Resonance Spectroscopy
-
Reactions of the nitrogen mustard drug 2-chloro-N-(2-chloroethyl)-N-methylethanamine with nucleophiles in aqueous solution have been studied by 1H and 13C n.m.r. spectroscopy.Conditions have been devised for converting the mustard into the N-2-chloroethyl-N-methylaziridinium ion which has been characterized by 1H n.m.r. spectroscopy.To assist the studies of reactions of the mustard by 13C n.m.r. spectroscopy, it has been prepared labelled at both C-2 atoms by 13C.It is shown that reactions of the mustard with strong nucleophiles (e.g. thiosulphate) proceed to a product of disubstitution, without the aziridinium ion being detected spectroscopically, although its intermediacy is inferred by examining the distribution of 13C in product from 13C-labelled mustard.Less reactive nucleophiles (e.g. thiourea) yield a product of disubstitution via spectroscopically detected intermediates (aziridinium ion and monosubstituted intermediate).Relatively weak nucleophiles (e.g. guanosine) did not give detectable products of substitution; cis- and trans-NN'-2-chloroethyl-NN'-methylpiperazinium dichloride were formed via the aziridinium ion.The reaction of the mustard with excess of ammonia gives a 3 : 2 ratio of 2-amino-N-(2-aminoethyl)-N-methylethanamine and N-methylpiperazine.The distribution of 13C label in these products derived from 13C-labelled drug shows that the triamine is formed via aziridinium intermediates, whilst the piperazine arises via intramolecular cyclisation of the intermediate 2-amino-N-(2-chloroethyl)-N-methylethanamine.
- Golding, Bernard T.,Kebbell, Michael J.,Lockhart, Ian M.
-
p. 705 - 714
(2007/10/02)
-