Polyetherols obtained from 6‐aminouracil and ethylene carbonate

Abstract

The reactions of 6-aminouracil with ethylene carbonate were investigated. Potassium carbonate or 1,4-diazabicyclo[2.2.2]octane was used as a catalyst. An excess of ethylene carbonate was applied in the syntheses. In this way, polyetherols with 1,3-pyrimidine rings in their structure were prepared. The structure of the products was analyzed with infrared, proton nuclear magnetic resonance, and matrix-assisted laser desorption/ionization time-of-flight techniques. Some physical properties and the thermal stability of the prepared polyetherols were investigated.

Synthesis of polyetherols with 1,3-pyrimidine ring using 6-aminouracil, ethylene carbonate and propylene oxide

“…Viscosity of the product obtained at 140 ºC is smaller than that for the product obtained at 160 ºC. IR and 1 H-NMR spectra of both products are practically the same as hydroxyethyl derivatives described in earlier works [5]. Their structure can be described by equation (II), where R = -H, and x + y + z + w = 5.…”

“…Previous studies on reactions of 6-AU and other azacyclic compounds with oxiranes [5,7,8] and alkylene carbonates [6, 9 13] show that both ways of syntheses have some disadvantages. The first method needs a very long time of conducting and removal of solvent and catalyst under reduced pressure.…”

“…Initially a reaction of 6-AU with EC was carried out using starting molar ratio 1:5 and the same operating conditions as described in [5] (catalyst -potassium carbonate; 4 g/mol 6-AU; temperature 160 ºC). Next, similar syntheses were carried out at temperature 140 and 120 ºC.…”

“…These polyetherols can be obtained in reactions of 6-aminouracil (6-AU) with excess of oxiranes (I) [4] or alkylene carbonates (II) [5,6]. where: R = -H, -CH 3 , 3,0 ≤ x + y + z ≤ 10,4.…”

“…Reactions of 6-AU with ethylene carbonate (EC) occur at 160 ºC temperature, in the presence of potassium carbonate. Reactions with propylene carbonate (PC) occur at temperature 180 ºC, in the presence of DABCO and potassium carbonate as catalysts [5,6]. Time of syntheses was within 5.…”