New acetyl derivatives of uracil,
6-methyluracil, and thymine were
obtained in the course of an unconventional synthesis in methylene
chloride. It was shown that products with the acetyloxymethyl fragment
are formed according to a mechanism different from that for products
with the acetyloxyethyl group. In particular, for uracil it was proven
that the reaction with Ac2O, TEA, and CH2Cl2 leads to 1-acetyloxymethyluracil, where the N
1 substituent is composed of the −CH2– fragment that originated from CH2Cl2 and the 1-acetyloxy moiety from Ac2O. The reaction of
uracil with Ac2O, TEA, CH2Cl2, and
DMAP leads to an acetyloxyethyl derivative in which the −CH2–CH2– fragment originates from TEA
and the 1-acetyloxy moiety from Ac2O. A possible mechanism
for the formation of new compounds was suggested and supported by
the density functional theory/B3LYP quantum mechanical calculations.
New compounds (39 in total, including seven deuterated) were fully
characterized by nuclear magnetic resonance and high-resolution mass
spectrometry techniques.