Ethyl 10-cyano-7-hy-droxy-6-oxo-3-phenyl-8,9,10,10a-tetra-hydro-6H-benzo[c]chromene-10-carboxyl-ate.

In the title compound, C23H19NO5, the cyano group adopts an axial orientation and the ester group an equatorial orientation. The dihedral angle between the pendant phenyl group and the benzene ring of the fused-ring system is 25.97 (8)°. Intra-molecular O-H⋯O and C-H⋯O hydrogen bonds are observed and the packing is consolidated by C-H⋯O and C-H⋯π inter-actions.

Synthesis of 7-hydroxydibenzopyran-6-ones via benzannulation of coumarins.

We have successfully demonstrated a facile synthesis of a variety of 7-hydroxydibenzopyran-6-ones via a two-step protocol from 3-acylcoumarins having a latent Nazarov dienone functionality. Condensation of 3-acylcoumarins and ethyl cyanoacetate under basic (wet K2CO3) and microwave irradiation conditions followed by decarboethoxylative aromatization with Br2 or DDQ furnished dibenzopyran-6-ones in high yields. The formation of ring C of the dibenzopyran-6-one motif critically depended on an active methylene compound and C7 substitution on coumarins. The Ar-Br or ArOTf substitution in dibenzopyran-6-ones was leveraged for the palladium-catalysed Suzuki coupling with diverse aryl boronic acids to increase the structural diversity. Reductive decyanation of C10 cyano dibenzopyran-6-ones furnished some of the isomers of urolithin A.

Crystal structure analysis of ethyl 6-(4-meth-oxy-phen-yl)-1-methyl-4-methyl-sulfanyl-3-phenyl-1H-pyrazolo-[3,4-b]pyridine-5-carboxyl-ate.

In the title compound, C24H23N3O3S, the dihedral angle between the fused pyrazole and pyridine rings is 1.76 (7)°. The benzene and meth-oxy phenyl rings make dihedral angles of 44.8 (5) and 63.86 (5)°, respectively, with the pyrazolo-[3,4-b] pyridine moiety. An intra-molecular short S⋯O contact [3.215 (2) Å] is observed. The crystal packing features C-H⋯π inter-actions.

6-Ethyl-N-methyl-3-nitro-4-nitro-methyl-4H-chromen-2-amine.

In the title compound, C(13)H(15)N(3)O(5), the O and N atoms of the nitro-methyl group and the methyl C atom of the ethyl group are disordered over two sets of sites with refined occupancies of 0.629 (7):0.371 (7) and 0.533 (8):0.467 (8), respectively. The dihydro-pyran ring has an extremely flattened conformation. An intra-molecular N-H⋯O hydrogen bond occurs. In the crystal, pairs of N-H⋯O hydrogen bonds link mol-ecules, forming inversion dimers. In addition, weak inter-molecular C-H⋯O hydrogen bonds are also present.

3-Benzyl-6-benzyl-amino-1-methyl-5-nitro-1,2,3,4-tetra-hydro-pyrimidine.

In the title compound, C(19)H(22)N(4)O(2), the tetra-hydro-pyrimidine ring adopts an envelope conformation (with the N atom connected to the benzyl group representing the flap). This benzyl group occupies a quasi-axial position. The two benzyl groups lie over the tetra-hydro-pyridimidine ring. The amino group is a hydrogen-bond donor to the nitro group.

2-(Nitromethylene)-1,3-dithietane

In the crystal structure of the title compound, C(3)H(3)NO(2)S(2), the four-membered C(2)S(2) ring is planar, as is the whole molecule. The short intramolecular S.O distance of 2.687 (2) A shows the five-atom system to be conjugated. The molecules pack as a two-dimensional network in the (010) plane through short intermolecular S.O [2.900 (2) and 3.077 (2) A] interactions.