Solubility modelling and thermodynamic dissolution functions of phthalimide in ten organic solvents

https://doi.org/10.1016/j.jct.2015.10.024Get rights and content

Highlights

  • The solubility of phthalimide in ten organic solvents were determined.

  • The solubility were correlated with four thermodynamic models.

  • The dissolution thermodynamic properties of solution were obtained.

Abstract

In this work, a high performance liquid chromatography (HPLC) was employed to determine the solubilities of phthalimide in methanol, isopropanol, n-propanol, ethyl acetate, acetonitrile, i-butanol, n-butanol, toluene, acetone and ethanol at temperatures ranging from (283.15 to 318.15) K under 0.1 MPa. The solubility of phthalimide in a fixed solvent increases with an increase in temperature. At a certain temperature, the solubility in different solvents decreases according to the following order: acetone > ethyl acetate > (methanol, isopropanol, n-propanol, acetonitrile, i-butanol, n-butanol, ethanol) > toluene. Four models, modified Apelblat equation, λh equation, Wilson model and NRTL model were employed to correlate the solubility of phthalimide in the solvents studied. The evaluated solubilities provide better agreement with the modified Apelblat equation than the other three models. The four thermodynamic models are all acceptable for correlating the solubility of phthalimide in the solvents studied. Furthermore, the standard dissolution enthalpy and excess enthalpy of the solutions were obtained. The dissolution process of phthalimide in the selected solvents is discussed.

Introduction

Phthalimide is an important chemical intermediate. The use of phthalimide and its derivatives is widely spread in dyestuffs, agriculture, medicine, and many other fields [1], [2], [3], [4], [5]. In industry, phthalimide can be prepared by treating phthalic anhydride with ammonia [6], [7], [8] or by treating the anhydride with ammonium carbonate or urea [9], [10] and or by ammoxidation of ortho-xylene [11]. At present, the commercial preparation method of phthalimide is using phthalic anhydride as raw material. Although the yield of phthalimide is relatively high by this method, the crude product usually contains some unreacted phthalic anhydride. Extreme difficulty is encountered in separating the phthalimide of high purity from the reaction mixture because of the extremely poor solubility of phthalimide in water. With the development of industry, the requirements for product purity are becoming greater. The crude phthalimide restricts its applications in many aspects.

It is well-known that crystallization is an important process during purifying a solid compound. Knowledge of solubility is of significance in designing chemical and pharmaceutical industrial processes. In previous works, some purification methods have been proposed to separate the phthalimide directly with high purity [12], [13], however, the cost of these processes is relatively high. To the best of the authors’ knowledge, crystallization is an effective method in phthalimide purification. Unfortunately, values of the solubility of phthalimide in solvents are very scare in previous publications. Solubility may be employed to optimise the basic design of the crystallization process and improve the purity of phthalimide which is of great significance in the purification procedure of phthalimide via the method of solvent crystallization. Thus, in order to obtain the product with high purity, investigation of the phthalimide solubility in different solvents at various temperatures and the thermodynamic properties of solution are especially necessary in industry.

The purposes of the work are to (1) determine the solubility of phthalimide in methanol, isopropanol, n-propanol, ethyl acetate, acetonitrile, i-butanol, n-butanol, toluene, acetone and ethanol at temperatures ranging from (283.15 to 318.15) K by high performance liquid chromatography (HPLC), (2) correlate solubility data using the Apelblat equation, λh equation, Wilson model and NRTL model, and (3) evaluate the thermodynamic properties for the solutions of phthalimide in different solvents.

Section snippets

Materials

Phthalimide having a mass fraction of 0.980 was purchased from Taixing Haoshen Chemical Co., Ltd. It was recrystallized three times in acetone. The content of phthalimide employed in solubility determination was 0.994 in mass fraction, which was further analysed by a high performance liquid chromatography (HPLC). The solvents were of analytical grade and used without additional purification. The detailed information of the materials employed in this work is tabulated in table 1.

Solubility determination

In the present

Solubility values

The mole fraction solubilities determined in this work for phthalimide in methanol, isopropanol, n-propanol, ethyl acetate, acetonitrile, i-butanol, n-butanol, toluene, acetone and ethanol within the temperature range from (283.15 to 318.15) K are tabulated in table 2, and plotted in FIGURE 1, FIGURE 2. Furthermore, the van’t Hoff plots of ln (x) versus inverse of absolute temperature in different solvents are graphically shown in figure 3. We can find from table 2 and FIGURE 1, FIGURE 2 that,

Conclusions

The equilibrium solubility data of phthalimide in ten organic solvents were determined experimentally at the temperatures between (283.15 and 318.15) K under 0.1 MPa by means of the high performance liquid chromatography (HPLC). The solubility values of phthalimide in the pure solvents increase with increasing temperature, but the increments are different for different solvents. At a certain temperature, the solubilities rank as acetone > ethyl acetate > (methanol, isopropanol, n-propanol,

Acknowledgements

We thank the National Natural Science Foundation of China for their support (Project number: 21406192). Furthermore, the Yangzhou City Science and Technology Bureau, China (Project number: 2012038-3 and YZ2011139), are also appreciated.

References (28)

  • A.M. Aronov et al.

    Tetrahedron Lett.

    (1998)
  • A.S. Fouda et al.

    Desalination

    (2006)
  • A. Apelblat et al.

    J. Chem. Thermodyn.

    (1999)
  • H. Buchowski et al.

    Fluid Phase Equilib.

    (1986)
  • J. Fang et al.

    J. Chem. Thermodyn.

    (2015)
  • J.H. Choi et al.

    Fiber Polym.

    (2010)
  • J.H. Choi et al.

    Color. Technol.

    (2008)
  • P.M. Lorz et al.

    Ullmann’s Encyclopedia of Industrial Chemistry

    (2005)
  • K. Gerhard, G. Johannes, Continuous preparation of phthalimide, US Patent 4,419,519, Dec 6,...
  • E. Hetzel, L. Vogel, G. Rotermund, H.C. Horn, Continuous manufacture of phthalimide, US Patent 486,678, Mar 2,...
  • H. Miyaji, A. Miura, T. Kimura, Production of phthalimide compound, JP Patent 2,001,122,858, May 8,...
  • K.D.P. NII, Process for obtention of phthalimide, WO Patent 8,503,291, Aug 1,...
  • I.S. Poddubnyj, A.A. Kuznetsov, L.N. Gura, S.A. Sergeev, I.JU. Kosov, Method of synthesis of phthalimide, RU Patent...
  • M. Ikeda, S. Terui, T. Kanzaki, K. Sano, A. Inoue, Production of phthalimide and catalyst composition therefore, JP...
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