1,4,7,10-Tetraazacyclododecane incorporating salicylic acid moieties synthesis and properties

Membrane Filtration of Lead, Cobalt, and Nickel in Water and Fertilizer Samples for Enrichment/Separation and Flame Atomic Absorption Spectrometric Determination

“…The sample volume is another key factor in the preconcentration studies to obtain high preconcentration factors (44)(45)(46)(47)(48)(49). The influence of sample solution volume on the recovery of the analyte elements was investigated in the 25-200 mL range.…”

“…The negative or positive effects of the main components of real samples on the analyte signals for the spectroscopic determination are called "Matrix Effects" (49)(50)(51)(52)(53). Therefore, sample pretreatment is required prior to analysis to reduce matrix effects.…”

Synthesis of tryptamines by the Fischer method using synthetic precursors and latent forms of amino-butanal (review)

“…* 2 5-CH 2 CO 2 Et, 5-(CH 2 ) 3 CO 2 Et, and 5-CH 2 CN were also prepared by this method (yields not given). * 3 The use of A leads to a large amount of side products [240]. * 4 The hydrazone was isolated intermediately.…”

“…Chloroethylindoles 52 containing accepting groups are formed with low yields. At the same time, for example, in the reaction of 4-chloro-2-pentanone with N-benzyl-5-methoxyphenylhydrazine 1-benzyl-5-methoxy-2-methylchloroethylindole is formed with a yield of 67% during the indolization of the corresponding hydrazone in a 0.4 N ethanol solution of HCl (241 [240] In reaction with ammonia and amines the chloroethylindoles form tryptamines (65-88%) and N-alkyltryptamines (50-85%) [66,233,240,241].…”

“…The formation of alkylation products 58 [261,262,240], including high-molecular polymers 59 [262] and other side products, is therefore possible under the conditions of the Fischer reaction, and they greatly complicate the isolation of the desired tryptamines. In order to suppress the formation of the condensation products it is possible to use hydrazines with a sulfamide group in the latent isothiazolone form [261] or protected by an ethoxycarbonyl group [234] in the Fischer reaction.…”