In 2003,Samaritoni, Jack G.; Demeter, David A.; Gifford, James M.; Watson, Gerald B.; Kempe, Margaret S.; Bruce, Timothy J. published 《Dihydropiperazine Neonicotinoid Compounds. Synthesis and Insecticidal Activity》.Journal of Agricultural and Food Chemistry published the findings.Formula: C4H7NO2S The information in the text is summarized as follows:
Various isomeric piperazines were prepared successfully via regioselective monothionation of their resp. diones. Preparation of the precursor unsym. N-substituted piperazinediones from readily available diamines is the key to this selectivity. The piperazine ring system, as exemplified in I [X = NCN, Y = O, Z = H2, R1 = Me; (II)] and III (R2 = 2-chloro-1,3-thiazol-5-yl), has been shown to be a suitable bioisosteric replacement for the imidazolidine ring system contained in neonicotinoid compounds However, placement of the cyanoimino electron-withdrawing group further removed from the pyridine ring, as in I (X = O, Y = NCN, Z = H2, R1 = H), or relocation of the carbonyl group, as in I (X = NCN, Y = H2, Z = O, R1 = Me), results in significantly decreased bioisosterism. The piperazine ring system of II and III (R = 2-chloro-1,3-thiazol-5-yl) also lends a degree of rigidity to the mol. that is not offered by the inactive acyclic counterpart 2-[(6-chloropyridin-3-yl)-methyl-(methyl)amino]-2-(cyanoimino)-N,N-dimethylacetamide. A pharmacophore model is proposed that qual. explains the results on the basis of good overlap of the key pharmacophore elements of II and imidacloprid; the less active regioisomers feature a smaller degree of overlap. The experimental process involved the reaction of Ethyl 2-amino-2-thioxoacetate(cas: 16982-21-1Formula: C4H7NO2S)
Ethyl 2-amino-2-thioxoacetate(cas: 16982-21-1) belongs to anime. Aniline, ethanolamines, and several other amines are major industrial commodities used in making rubber, dyes, pharmaceuticals, and synthetic resins and fibres and for a host of other applications. Most of the numerous methods for the preparation of amines may be broadly divided into two groups: (1) chemical reduction (replacement of oxygen with hydrogen atoms in the molecule) of members of several other classes of organic nitrogen compounds and (2) reactions of ammonia or amines with organic compounds.Formula: C4H7NO2S
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