Synthesis and Properties of sym-Triazine Derivatives. 18. Synthesis of N-Substituted 2,4-Diamino-6-(benzothiazolyl-2-thiomethyl)-sym-triazines

The condensation of methyl benzothiazolyl-2-thioacetate with N-substituted biguanides in the presence of sodium methylate gave 2-amino-4-(RR'-amino)-6-(benzothiazolyl-2-thiomethyl)-sym-triazines. In a number of cases the 1,1-disubstituted 5-(benzothiazolyl-2-thioacetyl)biguanides could also be separated and these could be cyclized by refluxing in DMF to the corresponding substituted sym-triazines described. The latter type of compound was also synthesized by treating 2-amino-4-trichloromethyl-6-(benzothiazolyl-2-thiomethyl)-sym-triazine with primary and secondary aliphatic and heterocyclic amines or by the reaction of N-substituted 2,4-diamino-6-chloromethyl-sym-triazines with 2-mercaptobenzothiazole.     

Metformin and Moroxidine Determination With Cu (II)

Abstract

Conductometric titrations of metformin and moroxidine are reported. The procedure is based on the copper-biguanide reaction which gives a pink soluble complex. Studies at several pH values and presence of NH₃ are carried out. NaOH-NH₃ (1:15) are added to 5 ml of biguanide aqueous solution and diluted to 60 ml and titrated with copper sulphate. Concentrations of metformin in 205x10^?4-1,7x10^?3 M range are determined. Foreign species presence is studied too.     

Determination of metformin and other biguanides in forensic whole blood samples by hydrophilic interaction liquid chromatography-electrospray tandem mass spectrometry

Metformin is an anti-diabetic drug in the biguanide class which also includes phenformin and buformin. Because of the potential adverse effects of the biguanides, a reliable liquid chromatography-tandem mass spectrometry method using pneumatically assisted electrospray ionization was developed for the quantification of the drugs in both live and post-mortem human whole blood. The blood proteins were precipitated by the addition of a mixture of methanol and acetonitrile, and the extract was cleaned up by cation-exchange solid-phase extraction to eliminate ion suppression effects. The separation was performed by hydrophilic interaction liquid chromatography. Matrix-matched calibrants combined with isotope dilution of metformin were used for calibration. The detection limits were 0.01 mg/L for metformin and phenformin and the relative intra-laboratory reproducibility standard deviations were less than 6% at concentrations of 1-10 mg/L. The mean true recoveries were greater than 86%.