M. Al-Omar, A. M. Al-Obaid, N. El‐Brollosy
Apr 23, 2010
Citations
0
Influential Citations
11
Citations
Journal
Synthetic Communications
Abstract
The reaction of 2,6-difluorobenzaldehyde, 2-chloro-6-fluorobenzaldehyde, or 2,6-dichlorobenzaldehyde and ethyl cyanoacetate and thiourea, in the presence of potassium carbonate, yielded a mixture of the cis- and trans-5,6-dihydro-2-thiouracil derivatives 4a–c. Compounds 4a–c, which were found to be resistant to atmospheric oxidation even at high temperatures, were successfully dehydrogenated to 5a–c via prolonged heating with chloranil in toluene. Meanwhile, oxidation of the dihydro derivative 4b by heating in dimethylsufphoxide for 10 min yielded the corresponding 2-thiouracil 5b in 73% yield, in addition to the disulfide derivative 7 as a minor product.