90559-06-1

Upstream product

• 64-17-5 ethanol 
• 471-29-4 1-methylguanidine 
• 93-89-0 benzoic acid ethyl ester 
• 860721-31-9 N-(1-methyl-4-oxo-4,5-dihydro-1H-imidazol-2-yl)-benzamide 
• 60-24-2 2-hydroxyethanethiol 

Downstream Products

• 60-24-2 2-hydroxyethanethiol 
• 115822-11-2 3-methylamino-5-phenyl-1,2,4-oxadiazole 
• 27182-64-5 3-methylamino-5-phenyl-1,2,4-thiadiazole 

Relevant academic research and scientific papers

Evaluation of transnitrosating ability of N-nitrosoguanidines to alkyl thiols and thiol amino acids

The transfer of the nitroso group from 1-nitroso-1-methyl-3-tolylsulfonylguanidine (NOTSG) and 1-nitroso-1-methyl-3-benzoylguanidine (NOBMG) to some thiols, including the amino acid cysteine, was studied in a pH range between 7 and 12. The measured apparent bimolecular rate constant of transnitrosation (ktrapp) revealed a bell-shaped pH dependence that clearly indicates that both nitrosoguanidines react through the corresponding neutral form, and the nucleophiles in the thiolate anion form to give the corresponding S-nitrosothiol. Regarding cysteine, the existence of three macroscopic acidity constants influenced the kinetic behavior of the transnitrosation reaction. Transnitrosation rates (ktr) of the two possible nucleophilic species were obtained and it was found that NOBMG has lower thiol transnitrosation capacity due to the lower electron-withdrawing effect of benzoyl group and to the possible stabilization of the anionic structure as a consequence of the establishment of the intramolecular hydrogen bond. The ktr values of the studied nucleophiles were calculated and a Br?nsted-type plot was established giving unexpected negatives βnuc(βnuc(NOBMG)=-0,17 and βnuc(NOTSG)=-0,11). The atypical βnuc values were attributed to the need for previous desolvation of the nucleophile.

Kinetics and mechanism of acid hydrolysis of 1-methyl-1-nitroso-3-p-tolylsulfonylguanidine and 1-methyl-1-nitroso-3-benzoylguanidine

Kinetics of acid hydrolysis of 1-methyl-1-nitroso-3-p-tolylsulfonylguanidine 2 and of two 1-methyl-1-nitroso-3-benzoylguanidines (4-unsubstituted and 4-chloro) 5 and 6 have been studied. For the acid hydrolysis of 1-methyl-1-nitroso-3-p-tolylsulfonylguanidine 2, the absence of catalysis by thiocyanate ion, and the value of the kinetic solvent isotope effect indicate that either a rate determining proton transfer followed by fast denitrosation or a concerted pathway is involved in the mechanism. In the case of the acid hydrolysis of 1-methyl-1-nitroso-3-benzoylguanidines 5 and 6 it was observed that the protonated form decomposes via two parallel pathways. One involves a slow nucleophilic attack concerted with an intramolecular proton transfer, and the other a slow concerted denitrosation, where a second proton transfer and NO+ expulsion are simultaneous.