3-Methyl-benzo[1,2-c:5,4-c']dichromen-6(8H)-one.

The title compound, C21H14O3, crystallizes with eight independent mol-ecules (A-H) in the asymmetric unit which are arranged in four groups of two mol-ecules each (AB, CD, EF and GH). In each mol-ecule, the pyran-2-one ring is planar (r.m.s. deviations vary from 0.001 to 0.017 Å), while the pyran ring has a screw-boat conformation. In the crystal, mol-ecules stack in two columns, along the [10-1] direction, composed of mol-ecules C, B, E and G, and D, A, F and H. Mol-ecules A and F are linked via C-H⋯O hydrogen bonds. In addition, there are a number of C-H⋯π contacts present involving all of the mol-ecules. These inter-actions result in the formation of a three-dimensional network.

rac-4a,10b-cis,10b,5c-trans-5-(7-Methyl-2-oxo-2H-chromen-4-yl)-3,4,4a,5,6,10b-hexa-hydro-2H-pyrano[3,2-c]quinoline.

In the racemic title compound, C(22)H(21)NO(3), the nitro-gen-containing ring of the pyran-oquinoline moiety adopts a slightly distorted half-chair conformation and the oxygen-containing ring adopts a slightly distorted chair conformation. The benzene rings make a dihedral angle of 84.97 (8)°. In the crystal, weak C-H⋯O inter-actions link the mol-ecules into chains extending along the a-axis direction.

Ultrasound-promoted synthesis of 1-amidoalkyl-2-naphthols via a three-component condensation of 2-naphthol, ureas/amides, and aldehydes, catalyzed by sulfamic acid under ambient conditions.

A three-component one-pot condensation of 2-naphthol, ureas/amides and aldehydes catalyzed by sulfamic acid, under ultrasound irradiation and ambient conditions gives 1-amidoalkyl-2-naphthols in excellent yield and in short time.