2,4(1H,3H)-Pyrimidinedione, 1,3-dimethyl-

• Formula: C₆H₈N₂O₂
• Molecular weight: 140.1399
• IUPAC Standard InChI: InChI=1S/C6H8N2O2/c1-7-4-3-5(9)8(2)6(7)10/h3-4H,1-2H3 Copy

  
• IUPAC Standard InChIKey: JSDBKAHWADVXFU-UHFFFAOYSA-N Copy
• CAS Registry Number: 874-14-6
• Chemical structure:
  This structure is also available as a 2d Mol file
• Other names: Uracil, 1,3-dimethyl-; N,N'-Dimethyluracil; N1,N3-Dimethyluracil; 1,3-Dimethyluracil; 2,4-Dihydroxy-1,3-dimethylpyrimidine
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Phase change data
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • Mass spectrum (electron ionization)
• Options:
  • Switch to calorie-based units

Data at NIST subscription sites:

• NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.

Phase change data

Go To: Top, References, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data compiled as indicated in comments:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
AC - William E. Acree, Jr., James S. Chickos
DH - Eugene S. Domalski and Elizabeth D. Hearing

Enthalpy of sublimation

Entropy of sublimation

Enthalpy of fusion

Entropy of fusion

Enthalpy of phase transition

References

Go To: Top, Phase change data, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Zielenkiewicz, Zielenkiewicz, et al., 1984
Zielenkiewicz, A.; Zielenkiewicz, W.; Malanowski, S., Thermodynamic Excess Functions of Dilute Aqueous Solutions of Alkylated Pyrimidines and Aminopurines and Caffeine, Thermochim. Acta, 1984, 74, 95. [all data]

Beak and White, 1982
Beak, P.; White, J.M., Relative enthalpies of 1,3-dimethyl-2,4-pyrimidinedione, 2,4-dimethoxypyrimidine, and 4-methoxy-1-methyl-2-pyrimidinone: estimation of the relative stabilities of two protomers of uracil, J. Am. Chem. Soc., 1982, 104, 7073-7077. [all data]

Imamura, Takahashi, et al., 1989
Imamura, A.; Takahashi, K.; Murata, S.; Sakiyama, M., Standard enthalpies of formation of trimethyl cyanurate, malonamide, and 1,3-dimethyluracil, J. Chem. Thermodyn., 1989, 21, 237-246. [all data]

Murata, Sakiyama, et al., 1985
Murata, S.; Sakiyama, M.; Seki, S., Sublimation calorimetric studies using a calvet microcalorimeter, Thermochimica Acta, 1985, 88, 1, 121-126, https://doi.org/10.1016/0040-6031(85)85419-8 . [all data]

Clark, Peschel, et al., 1965
Clark, L.B.; Peschel, G.G.; Tinoco, I., Jr., Vapor spectra and heats of vaporization of some purine and pyrmidine bases, J. Phys. Chem., 1965, 69, 3615. [all data]

Brunetti, Piacente, et al., 2000
Brunetti, Bruno; Piacente, Vincenzo; Portalone, Gustavo, Sublimation Enthalpies of Some Methyl Derivatives of Uracil from Vapor Pressure Measurements, J. Chem. Eng. Data, 2000, 45, 2, 242-246, https://doi.org/10.1021/je9902802 . [all data]

Teplitsky, Yanson, et al., 1980
Teplitsky, A.B.; Yanson, I.K.; Glukhova, O.T.; Zielenkiwicz, A.; Zielenkiewicz, W.; Wierzchowski, K.L., Thermochemistry of aqueous solutions of alkylated nucleic acid bases, Biophysical Chemistry, 1980, 11, 1, 17-21, https://doi.org/10.1016/0301-4622(80)85003-4 . [all data]

Nowak, Szczepaniak, et al., 1978
Nowak, M.J.; Szczepaniak, K.; Barski, A.; Shugar, D.Z., Z. Naturforsch. C, 1978, 33C, 876. [all data]

Clark, Peschel, et al., 1965, 2
Clark, L.B.; Peschel, G.G.; Tinoco, I., Jr., Vapor spectra and heats of vaporization of some purine and pyrimidine bases, Not In System, 1965, 3615-3618. [all data]

Zielenkiewicz, Zielenkiewicz, et al., 1984, 2
Zielenkiewicz, A.; Zielenkiewicz, W.; Malanowski, S., Thermodynamic excess functions of diluted aqueous solutions of alkylated pyrimidines and amino purines, and caffeine, Thermochim. Acta, 1984, 74, 95-111. [all data]

Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D., Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III, J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985 . [all data]

Sakiyama and Imamura, 1989
Sakiyama, M.; Imamura, A., Thermoanalytical characterization of 1,3-dimethyluracil and malonamide crystals, Thermochim. Acta, 1989, 142(2), 365-370. [all data]

Notes

Go To: Top, Phase change data, References

• Symbols used in this document:
  

  Tfus	Fusion (melting) point
  ΔHtrs	Enthalpy of phase transition
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔsubH	Enthalpy of sublimation
  ΔsubH°	Enthalpy of sublimation at standard conditions
  ΔsubS	Entropy of sublimation
  ΔvapH°	Enthalpy of vaporization at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
• The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
• Customer support for NIST Standard Reference Data products.