Methyl 4‐(4‐fluorophenyl)‐6‐methyl‐2‐oxo‐1,2,3,4‐tetrahydropyrimidine‐5‐carboxylate, (I), was found to exhibit solvatomorphism. The compound was prepared using a classic Biginelli reaction under mild conditions, without using catalysts and in a solvent‐free environment. Single crystals of two solvatomorphs and one anhydrous form of (I) were obtained through various crystallization methods. The anhydrous form, C₁₃H₁₃FN₂O₃, was found to crystallize in the monoclinic space group C2/c. It showed one molecule in the asymmetric unit. The solvatomorph with included carbon tetrachloride, C₁₃H₁₃FN₂O₃·0.25CCl₄, was found to crystallize in the monoclinic space group P2/n. The asymmetric unit revealed two molecules of (I) and one disordered carbon tetrachloride solvent molecule that lies on a twofold axis. A solvatomorph including ethyl acetate, C₁₃H₁₃FN₂O₃·0.5C₄H₈O₂, was found to crystallize in the triclinic space group P with one molecule of (I) and one solvent molecule on an inversion centre in the asymmetric unit. The solvent molecules in the solvatomorphs were found to be disordered, with a unique case of crystallographically induced disorder in (I) crystallized with ethyl acetate. Hydrogen‐bonding interactions, for example, N—H…O=C, C—H…O=C, C—H…F and C—H…π, contribute to the crystal packing with the formation of a characteristic dimer through N—H…O=C interactions in all three forms. The solvatomorphs display additional interactions, such as C—F…N and C—Cl…π, which are responsible for their molecular arrangement. The thermal properties of the forms were analysed through differential scanning calorimetry (DSC), hot stage microscopy (HSM) and thermogravimetric analysis (TGA) experiments.

中文翻译：

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4-（4-氟苯基）-6-甲基-2-氧-2-，1,2,3,4-四氢嘧啶-5-羧酸甲酯的无水和两种溶剂化形式的晶体结构。

发现4-（4-氟苯基）-6-甲基-2-氧-1,2,3,4-四氢嘧啶-5-羧酸甲酯（I）具有溶剂化态。该化合物是使用经典的Biginelli反应在温和的条件下，不使用催化剂且在无溶剂的环境中制备的。通过各种结晶方法获得两种溶剂化物和一种无水形式的（I）的单晶。发现无水形式C ₁₃ H ₁₃ FN ₂ O ₃在单斜空间群C 2 / c中结晶。显示不对称单元中有一个分子。包含四氯化碳C ₁₃ H ₁₃的溶剂化物发现FN ₂ O ₃ ·0.25CCl ₄在单斜空间群P 2 / n中结晶。不对称单元揭示了两个分子（I）和一个无序的四氯化碳溶剂分子，该分子位于双重轴上。发现在一个三斜晶空间群P中，一个分子的（I）溶剂化物包括乙酸乙酯C ₁₃ H ₁₃ FN ₂ O ₃ ·0.5C ₄ H ₈ O ₂结晶。）和不对称单元中一个反转中心的一个溶剂分子。发现溶剂化物形态中的溶剂分子是无序的，在（I）中用乙酸乙酯结晶的晶体学上引起无序的独特情况。氢键相互作用，例如N-H…O = C，C-H…O = C，C-H…F和C-H…π，通过N形成特征二聚体，从而有助于晶体堆积所有三种形式的-H…O = C相互作用。溶剂化物显示出额外的相互作用，例如CF…N和CCl…π，这是其分子排列的原因。通过差示扫描量热法（DSC），热台显微镜（HSM）和热重分析（TGA）实验分析了形式的热性质。