NMR spectroscopic analysis of 2-mercapto-5-methyl-1,3,4-thiadiazole in cefazolin.
A rapid, sensitive, and accurate method for the quantitative analysis of 2-mercapto-5-methyl-1,3,4-thiadiazole in cefazolin is presented. The method utilizes NMR spectroscopy and is based on the difference in the chemical shift of the methyl protons on free thiadiazole and the thiadiazole moiety of cefazolin.
Analysis of cacodylate injections by NMR spectroscopy.
An NMR procedure was developed for the assay of sodium cacodylate injection. The results obtained by this technique compare favorably with those obtained by the NF X method and atomic absorption spectrophotometry. The advantages of the NMR procedure over the other procedures are that it is highly specific for the cacodylate and that it is less time consuming.
Synthesis of 2,4-dideoxy-.beta.-D-erythro-hexopyranosyl nucleosides
The synthesis of 1-(2,4-dideoxy-β-D-erythro-hexopyranosyl)thymine (12) 1 was accomplished using two different synthetic routes. It was obtained starting either from 1,2:5,6-di-O-isopropylidene-α-D-glucofuranose or from tri-O-acetyl-D-glucal. The other modified nucleosides, with either a cytosine, guanine, or adenine moiety, were synthesized using the second reaction scheme. Deoxygenation reactions were accomplished with the (2,4-dichlorophenoxy)thiocarbonyl derivatives generated in situ