Crystal structure of 5,5 0 -[(4-fluorophenyl)- methylene]bis[6-amino-1,3-dimethyl- pyrimidine-2,4(1H,3H)-dione] Naresh Sharma, a Goutam Brahmachari, b Bubun Banerjee, b Rajni Kant a and Vivek K. Gupta a * a Post-Graduate Department of Physics & Electronics, University of Jammu, Jammu Tawi 180 006, India, and b Laboratory of Natural Products & Organic Synthesis, Department of Chemistry, Visva-Bharati University, Santiniketan 731 235, West Bengal, India. *Correspondence e-mail: vivek_gupta2k2@hotmail.com Received 20 August 2014; accepted 3 September 2014 Edited by A. J. Lough, University of Toronto, Canada In the title molecule, C 19 H 21 FN 6 O 4 , the dihedral angles between the benzene ring and essentially planar pyrimidine rings [maximum deviations of 0.036 (2) and 0.056 (2) A ˚ ] are 73.32 (7) and 63.81 (8)  . The dihedral angle between the mean planes of the pyrimidine rings is 61.43 (6)  . In the crystal, N— HO hydrogen bonds link molecules, forming a two- dimensional network parallel to (001) and in combination with weak C—HO hydrogen bonds, a three-dimensional network is formed. Weak C—H interactions and – interactions, with a centroid–centroid distance of 3.599 (2) A ˚ are also observed. Keywords: crystal structure; uracil derivatives; biological activity; pyrimi- dine scaffolds; bis-uracil derivatives. CCDC reference: 973485 1. Related literature For the biological activity of uracil derivatives, see: Muller et al. (1993); Buckle et al. (1994). For drugs containing purine moieties, see: Zhi et al. (2003); Devi & Bhuyan (2005). For the biological activity of pyrimidine scaffolds, see: Makarov et al. (2005); Deshmukh et al. (2009); Ibrahim & El-Metwally (2010). For the synthesis of bis-uracil derivatives, see: Karimi et al. (2013). For a related structure, see: Das et al. (2009). 2. Experimental 2.1. Crystal data C 19 H 21 FN 6 O 4 M r = 416.42 Orthorhombic, Pbca a = 14.6208 (6) A ˚ b = 11.3324 (7) A ˚ c = 22.6410 (12) A ˚ V = 3751.4 (3) A ˚ 3 Z =8 Mo K radiation  = 0.11 mm 1 T = 293 K 0.30  0.20  0.20 mm 2.2. Data collection Oxford Diffraction Xcalibur Sapphire3 diffractometer Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2010) T min = 0.862, T max = 1.000 9655 measured reflections 3665 independent reflections 2208 reflections with I >2(I) R int = 0.047 2.3. Refinement R[F 2 >2(F 2 )] = 0.052 wR(F 2 ) = 0.130 S = 1.04 3665 reflections 291 parameters H atoms treated by a mixture of independent and constrained refinement Á max = 0.19 e A ˚ 3 Á min = 0.20 e A ˚ 3 Table 1 Hydrogen-bond geometry (A ˚ ,  ). Cg is the centroid of the C7–C12 ring. D—HA D—H HA DA D—HA N15—H40O3A 0 0.96 (3) 1.96 (3) 2.916 (3) 174 (2) N18—H50O3A 0.93 (3) 1.88 (3) 2.803 (3) 170 (2) N15—H30O3A i 0.86 (3) 2.26 (3) 3.083 (3) 161 (3) N18—H60O3A 0 ii 0.91 (3) 2.14 (3) 3.007 (3) 159 (2) C13—H13AO3A i 0.96 2.41 3.154 (3) 134 C13—H13ACg iii 0.96 2.98 3.744 (3) 138 Symmetry codes: (i) x þ 1 2 ; y þ 3 2 ; z þ 1; (ii) x þ 1 2 ; y  1 2 ; z; (iii) x  1 2 ; y þ 3 2 ; z þ 1. Data collection: CrysAlis PRO (Oxford Diffraction, 2010); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); soft- ware used to prepare material for publication: PLATON (Spek, 2009). data reports o1098 Sharma et al. doi:10.1107/S1600536814019886 Acta Cryst. (2014). E70, o1098–o1099 ISSN 1600-5368