77196-87-3Relevant academic research and scientific papers
Preparation method of pentoxifylline impurity
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Paragraph 0023-0025, (2021/05/01)
The invention discloses a preparation method of a pentoxifylline impurity. The preparation method comprises the following steps: adding theobromine into an organic solvent, stirring, and adding a certain amount of alkali; slowly dropwise adding a halogenating reagent into a reaction system for reaction under a temperature control condition; after the reaction is finished, filtering the reaction liquid, adding alkali liquor into the obtained filtrate to adjust the pH value to 10-11, adding a solvent for extraction, and separating the liquid; and washing, drying, concentrating and purifying the organic phase to obtain a target product. The method is easy to operate and can be used for quickly preparing the high-purity pentoxifylline impurity.
Preparation and NMR study of 7,7'-(α,ω-alkanediyl)bis[theophylline], 1,1'-(α,ω-alkanediyl)bis[theobromine], and 1,1'-(α,ω-alkanediyl)bis[3-methyluracil]
Itahara,Imamura
, p. 203 - 209 (2007/10/02)
The treatment of theophylline, theobromine, and 3-methyluracil with X(CH2)(n)X (X = Br or I, n = 1-12) in N,N-dimethylformamide containing sodium hydride gave the corresponding 7,7'-(α,ω-alkanediyl)bis[theophylline], 1,1'-(α,ω-alkanediyl)bis[theobromine], and 1,1'-(α,ω-alkanediyl)bis[3-methyluracil]. The interaction of the theophylline, theobromine, and 3-methyluracil rings of these compounds was studied based on their 1H NMR spectra, and stacking of the two purine rings of 7,7'-(α,ω-alkanediyl)bis[theophylline] was observed.
