ABSTRACT

The present study reports a differential scanning calorimetry (DSC) study of the barbituric acid derivatives: 1,3-dimethylbarbituric acid [CAS 769-42-6], 5,5-dimethylbarbituric acid [CAS 24448-94-0], 1,3-diethylbarbituric acid [CAS 32479-73-5], 1,3,5-trimethylbarbituric acid [CAS 7358-61-4], 1,5,5-trimethylbarbituric acid [CAS 702-47-6], and tetramethylbarbituric acid [CAS 13566-66-0] in the temperature interval from T = 268 K to their respective melting temperatures. Temperatures, enthalpies and entropies of fusion, and the heat capacities of the solid compounds as a function of temperature are reported.

Compounds

#	Formula	Name
1	C6H8N2O3	1,3-dimethylbarbituric acid
2	C6H8N2O3	5,5-dimethylbarbituric acid
3	C8H12N2O3	1,3-diethylbarbituric acid
4	C7H10N2O3	1,3,5-trimethylbarbituric acid
5	C7H10N2O3	1,5,5-trimethylbarbituric acid
6	C8H12N2O3	1,3,5,5-tetramethylpyrimidine-2,4,6(1H,3H,5H)-trione

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Constraint	Phase	Method	#Points
POMD	1	Molar enthalpy of transition or fusion, kJ/mol ; Crystal			Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	1	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Small sample (50 mg) DSC	23
POMD	2	Molar enthalpy of transition or fusion, kJ/mol ; Crystal			Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	2	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	2	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Small sample (50 mg) DSC	54
POMD	3	Molar enthalpy of transition or fusion, kJ/mol ; Crystal			Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	3	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	3	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Small sample (50 mg) DSC	11
POMD	4	Molar enthalpy of transition or fusion, kJ/mol ; Crystal			Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	4	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	4	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Small sample (50 mg) DSC	17
POMD	5	Molar enthalpy of transition or fusion, kJ/mol ; Crystal			Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	5	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	5	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Small sample (50 mg) DSC	32
POMD	6	Molar enthalpy of transition or fusion, kJ/mol ; Crystal			Crystal Liquid Air at 1 atmosphere	DSC	1
POMD	6	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	DTA	1
POMD	6	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Small sample (50 mg) DSC	23

Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

Thermophysical Study of Several Barbituric Acid Derivatives by Differential Scanning Calorimetry (DSC)

Temprado, M.[Manuel], Roux, M. V.[MarIa Victoria], Ros, F.[Francisco], Notario, R.[Rafael], Segura, M.[Marta], Chickos, J. S.[James S.]

ABSTRACT