Abstract
A series of novel thiobarbituric acid derivatives
3a-c
, 5, and
12
were synthesized via the reaction of 4-benzoyl-1-cyanoacetylthiosemicarbazide (
1
) or its derivatives
2a-c
,
9
with malonic acid and acetyl chloride. Coupling of thiobarbituric acid derivatives
3a-c
and
5
with aromatic diazonium chlorides furnished a new series of the corresponding bisarylhydrazo-thiobarbituric dyes
4a-c
. The reaction of
5
with cyclohexanone and sulfur under Gewald reaction condition afforded thieno[2,3-d]pyrimidine derivative
21
, that condensed with p-anisladehyde to give 5-arylidene thiobarbituric acid derivative
22
. The reaction of
1
with phenyl isothiocyanate afforded the non-isolable adduct
23
which was used as a key intermediate for the synthesis of polyfunctionally substituted thiazolidinone and thiobarbituric ring systems.