2-Methyl­sulfanyl-1,2,4-triazolo[1,5-a]quinazoline-5(4H)-thione

In the title compound, C₁₀H₈N₄S₂, comprising fused six-, six- and five-membered rings, the mol­ecule is close to being planar (r.m.s. deviation of the non-H atoms = 0.041 Å). The S-bound methyl group is folded away from the single N atom of the triazole ring and the NH group of the six-membered ring, allowing for the formation of centrosymmetric eight-membered {...HNCN}₂ synthons in the crystal. The resulting inversion dimers are connected into supra­molecular stacks aligned along the b-axis direction by π–π inter­actions [centroid–centroid distances = 3.6531 (12) and 3.7182 (12) Å].

Ethyl 2-amino-4-(4-bromo­phen­yl)-6-meth­oxy-4H-benzo[h]chromene-3-carboxyl­ate

In the title compound, C₂₃H₂₀BrNO₄, the pyran ring has a flattened boat conformation with the O and methine C atoms lying to one side of the plane [0.160 (5) and 0.256 (6) Å, respectively] defined by the remaining atoms. Nevertheless, the 4H-benzo[h]chromene ring system approximates a plane (r.m.s. deviation = 0.116 Å) with the bromo­benzene ring almost perpendicular [dihedral angle = 83.27 (16)°] and the ester group coplanar [C—C—C—O = 3.4 (5)°]; the meth­oxy substituent is also coplanar [C—O—C—C = 174.5 (3)°]. In addition to an intra­molecular N—H...O(ester carbon­yl) hydrogen bond, the ester carbonyl O atom also forms an inter­molecular N—H...O hydrogen bond with the second amine H atom, generating a zigzag supra­molecular chain along the c axis in the crystal packing. The chains are linked into layers in the bc plane by N—H...Br hydrogen bonds, and these layers are consolidated into a three-dimensional architecture by C—H...π inter­actions.

3-Amino-1-(4-fluoro­phen­yl)-8-meth­oxy-1H-benzo[f]chromene-2-carbonitrile

The title compound, C₂₁H₁₅FN₂O₂, features an approximately planar 1H-benzo[f]chromene fused-ring system (r.m.s. deviation for the 14 non-H atoms = 0.052 Å), with the fluoro­benzene ring being almost perpendicular to this [dihedral angle = 85.30 (7) °]. The furan ring has a flattened half-chair conformation, with the methine C atom deviating by 0.132 (2) Å from the plane of the remaining atoms (r.m.s. deviation = 0.0107 Å). In the crystal, inversion dimers are formed via pairs of amine–cyano N—H...N hydrogen bonds. The dimers are connected into a three-dimensional architecture by C—H...N(cyano), C—H...π and π–π [inter­centroid distance = 3.6671 (10) Å] inter­actions.

3-Amino-1-(4-fluoro­phen­yl)-7-meth­oxy-1H-benzo[f]chromene-2-carbonitrile

In the title compound, C₂₁H₁₅FN₂O₂, the furan ring has a flattened half-chair conformation [the methine C atom lies 0.136 (2) Å above the C₅ plane which has an r.m.s. deviation of 0.0229 Å]. Overall, the 1H-benzo[f]chromene fused-ring system approximates a plane (r.m.s. deviation of the 14 non-H atoms = 0.049 Å). The fluoro­benzene ring is almost perpendicular to this plane [dihedral angle = 89.58 (8)°]. Zigzag supra­molecular tapes along the b axis are the most notable feature of the crystal packing. This arises through an alternating sequence of 12-membered {...HNC₃N}₂ and eight-membered {...HNCO}₂ synthons. These are connected into a three-dimensional architecture by π–π [inter­centroid distance for centrosymmetrically related fluoro­benzene rings = 3.5181 (10) Å] and C—H...π inter­actions.

2-Amino-4-(4-bromo­phen­yl)-6-meth­oxy-4H-benzo[h]chromene-3-carbonitrile

In the title compound, C₂₁H₁₅BrN₂O₂, the 14 non-H atoms of the 4H-benzo[h]chromene fused-ring system are approximately coplanar (r.m.s. deviation = 0.129 Å). Within this system, the 4H-pyran ring adopts a flattened half-chair conformation with the methine C atom lying 0.281 (4) Å above the plane of the remaining atoms (r.m.s. deviation = 0.0446 Å). The bromo­benzene ring is almost perpendicular to the fused-ring system [dihedral angle = 85.34 (13)°]. In the crystal, supra­molecular layers parallel to (101) are sustained by amine–cyano N—H...N and amine–meth­oxy N—H...O hydrogen bonds. The layers stack with inter­actions of the type (bromo­benzene)C—H...π(outer-C₆ ring of the fused-ring system) connecting them.

N′-[3-Cyano-4-(4-fluoro­phen­yl)-6-meth­oxy-4H-benzo[h]chromen-2-yl]-N,N-dimethyl­methanimidamide

In the title compound, C₂₄H₂₀FN₃O₂, despite the 4H-pyran ring having a flattened half-chair conformation [the methine C atom lies 0.257 (3) Å above the plane of the remaining atoms with an r.m.s. deviation of 0.0295 Å], the 14 non-H atoms of the 4H-benzo[h]chromene residue are approximately coplanar (r.m.s. deviation = 0.081 Å). The benzene ring is nearly perpendicular to this plane [dihedral angle = 76.18 (10)°], but the planar (r.m.s. deviation = 0.033 Å) dimethyl­methanimidamide substituent is coplanar [dihedral angle = 1.96 (12)°]. In the crystal, centrosymmetric dimeric aggregates arise from C—H...N inter­actions, and these are connected into supra­molecular layers in the ab plane by C—H...π and π–π [inter­centroid (central C₆ ring)...(outer C₆ ring)ⁱ distance = 3.8564 (14) Å] inter­actions.

2-(4-Fluoro­benzyl­idene)propane­dinitrile: monoclinic polymorph

The title compound, C₁₀H₅FN₂, is a monoclinic (P2₁/c) polymorph of the previously reported triclinic (P-1) form [Anti­pin et al. (2003). J. Mol. Struct. 650, 1–20]. The 13 non-H atoms in the title polymorph are almost coplanar (r.m.s. deviation = 0.020 Å); a small twist between the fluoro­benzene and dinitrile groups [C—C—C—C torsion angle = 175.49 (16)°] is evident in the triclinic polymorph. In the crystal, C—H...N inter­actions lead to supra­molecular layers parallel to (-101); these are connected by C—F...π inter­actions.

3-[(4-Phenyl­piperazin-1-yl)meth­yl]-5-(thio­phen-2-yl)-2,3-di­hydro-1,3,4-oxa­diazole-2-thione

In the title compound, C₁₇H₁₈N₄OS₂, the 2-thienyl ring is disordered over two co-planar, opposite orientations in a 0.684 (2): 0.316 ratio. The 1,3,4-oxa­diazole ring is almost co-planar with the attached 2-thienyl ring [dihedral angles of 5.34 (19) and 4.8 (5)° for the major and minor components, respectively]. The relative disposition of the thione- and ring-S atoms is anti for the major orientation of the 2-thienyl residue. Overall, the shape of the mol­ecule approximates the letter V. In the crystal, a three-dimensional architecture is consolidated by a combination of weak C—H...S and C—H...π contacts.