87122-95-0Relevant academic research and scientific papers
Regioselective Thermal [3+2]-Dipolar Cycloadditions of α-Diazoacetates with α-Sulfenyl/Sulfinyl/Sulfonyl-β-Chloroacrylamide Derivatives to Form Densely Functionalised Pyrazoles
Flynn, Aaran J.,Ford, Alan,Khandavilli, U. B. Rao,Lawrence, Simon E.,Maguire, Anita R.
supporting information, p. 5368 - 5384 (2019/06/24)
Highly regioselective synthetic methodology leading to densely functionalised C(3), C(4) and C(5) substituted pyrazoles 10a–q, 14a-i and 16a–g via thermal [3+2]-dipolar cycloaddition, of α-diazoacetates and α-thio-β-chloroacrylamides, at the sulfide, sulfoxide and sulfone levels of oxidation, is described. This method allows access to C(4)-sulfenyl or sulfonyl pyrazoles, through migration of the sulfur substituent at the sulfide and sulfone oxidation levels, while elimination of the sulfinyl group leading to 3,5-disubstituted pyrazoles, is observed. While the sulfide migration is readily rationalised, the carbon to carbon 1,2-sulfonyl migration is unprecedented and mechanistically intriguing. The synthetically versatile generation of densely functionalised pyrazoles containing substituents amenable to further modification offers advantages over alternative synthetic routes. Isolation of the N-alkylated pyrazoles 11a and 12a as by-products from the cycloaddition through further reaction of the pyrazoles 10 with excess α-diazoacetate, proved useful in rationalising the tautomeric behaviour evident in the NMR spectra of the pyrazoles, with the position of tautomeric equilibrium influenced by solvent and substituents.
Investigation of the synthetic and mechanistic aspects of the highly stereoselective transformation of α-thioamides to α-thio-β- chloroacrylamides
Murphy, Maureen,Lynch, Denis,Schaeffer, Marcel,Kissane, Marie,Chopra, Jay,O'Brien, Elisabeth,Ford, Alan,Ferguson, George,Maguire, Anita R.
, p. 1228 - 1241 (2008/02/03)
Treatment of a series of α-thioamides with N-chlorosuccinimide results in efficient transformation to the analogous α-thio-β- chloroacrylamides. The mechanistic pathway has been established through isolation and characterisation of intermediate compounds. The scope of the transformation has been explored - aryl and alkylthio substituents, primary, secondary and tertiary amides can be employed. In most instances, the chloroacrylamides are formed exclusively as the Z-stereoisomer; however, with tertiary propanamides or with amides derived from butanoic or pentanoic acid a mixture of E- and Z-stereoisomers is formed. The Royal Society of Chemistry.
2-(Arylthio)ethanamines and &α-(Arylthio)propionamides with Antidepressant Activity
Nair, M. D.,David, J.,Nagarajan, K.
, p. 940 - 947 (2007/10/02)
Reaction of aziridine with thiophenols affords 2-arylthioethanamines; with 2-methylaziridine, ring opening occurs regiospecifically to provide 1-arylthio-2-propanamines.The structure of one member of this group, 1-(4-chlorophenylthio)-2-propanamine (7), has been proved by other unambiguous syntheses. 7 and isomer 12 arise from the alkylation of 4-chlorothiophenol with 2-chloropropylamine as well as from the displacement of the tosyl group in 1-(4-chlorophenylthio)-2-tosyloxypropane (13).Alkylation of 4-chlorothiophenol with α-chloropropionamide affords 11 which leads to 12 on LAH reduction.Ethanamines and propanamines are converted into guanidines, amides, ureas and thioureas.Many arylthioethanamines, e.g. 7, 22, 28, 38 and 39 (as HCl salts) and α-arylthiopropionamides, e.g. 11, 86, 91, 93 and 96 exhibit good activity in the DOPA potentiation and reserpine antagonism tests.Among these, 7 HCl is the most potent and does not inhibit rat brain MAO activity.In clinical trials, C 2998-Go compares favourably with imipramine.
Mass Spectrometry of 2-Alkylthio-2-methylpropanoic Acids and Their Esters and Amides. Structural and Steric Effects on the McLafferty Rearrangement
Mori, Yuji,Fujiwara, Shigeru,Miyachi, Toshiko,Kitanishi, Hiroyuki,Oya, Masayuki,et al.
, p. 1505 - 1517 (2007/10/02)
The electron ionization mass spectra (MS) of S-methylated derivatives of N-(2-mercapto-2-methylpropanoyl)-L-cysteine and 2-alkylthio-2-methylpropanoic acids, as well as their esters and amides, were examined.Use of the deuterium labeling technique and accurate mass measurement supported the proposed fragmentation pathways.Extensive loss of CH2S from a molecular ion by the McLafferty rearrangementof a primary hydrogen is important in the MS of S-methyl compounds of amide derivatives.It was demonstrated that the intensity of the rearrangement ion decreases in the order of amide, ester, and acid, and in the case if amides the reaarangement is suppressed by the nonbonded interaction between methyl groups on the α carbon and the amide nitrogen.Keywords-N-(2-mercapto-2-methylpropanoyl)-L-cysteine; 2-alkylthio-2-methylpropanoic acid and methyl ester; 2-alkylthio-2-methylpropanamide; electron impact mass spectrometry; McLafferty rearrangement; steric interaction
