N-(1-Naphthyl)-10H-9-oxa-1,3-diazaanthracen-4-amine

In the molecule of the title compound, C21H15N3O, the 10H-9-oxa-1,3-diazaanthracene ring system is slightly bent, with dihedral angles of 3.99 (6) and 4.80 (6)° between the pyran ring and the pyrimidine and benzene rings, respectively. This ring system makes a dihedral angle of 85.23 (3)° with the naphthalene plane. In the crystal packing, molecules are linked by N—H⋯N hydrogen bonds into chains along the a axis and these chains are stacked along the b axis. The crystal is further stabilized by weak C—H⋯N and C—H⋯π interactions.

In the molecule of the title compound, C 21 H 15 N 3 O, the 10H-9oxa-1,3-diazaanthracene ring system is slightly bent, with dihedral angles of 3.99 (6) and 4.80 (6) between the pyran ring and the pyrimidine and benzene rings, respectively. This ring system makes a dihedral angle of 85.23 (3) with the naphthalene plane. In the crystal packing, molecules are linked by N-HÁ Á ÁN hydrogen bonds into chains along the a axis and these chains are stacked along the b axis. The crystal is further stabilized by weak C-HÁ Á ÁN and C-HÁ Á Á interactions.

Comment
Condensed heterocyclic systems are of considerable interest not only because of their potential biological activity but also because of their versatility as synthons in organic transformations (Bohme & Haake, 1976;Taylor & McKillop, 1970;Erian, 1993). A series of 1,6-naphthyrimidines have been demonstrated to possess antihuman cytomegalovirus (HCMV) activity (Falardeau et al., 2000;Bedard et al., 2000). Furthermore, chromenes and their fused heterocyclic derivatives have attracted a great deal of interest due to their wide applications in the field of pharmaceuticals (Martinez & Marco, 1997;Tandon et al., 1991). In view of these observations, we have synthesized title compound which is a new chromenopyrimidine molecule and its crystal structure was reported here.
In the crystal packing, N-H···N hydrogen bonds (Table 1, Fig. 2) link the molecules into chains along the a axis and these molecular chains are stacked along the b axis. The crystal is further stabilized by weak C-H···N and C-H···π interactions; Cg1 and Cg2 are the centroids of C1-C3/C11/N1-N2 and C4-C9 rings, respectively (Table 1).

Experimental
The title compound was obtained by vigorously stirring a solution of 2-amino-4H-chromene-3-carbonitrile 0.5 g (2.8 mmol) in 10 ml of dimethyl formamide dimethylacetal which has been heated to reflux for 2 h. Excess dimethyl formamide dimethyl acetal was removed and the residue obtained was dissolved in acetic acid (10 ml). Amine 0.41 g (2.8 mmol) was then added and heated to reflux for an additional 2 h. The reaction mixture was concentrated and finally the residue was purified by column chromatography using petroleum ether-ethyl acetate (60:40 v/v) to get desired compound as a crystalline solid 0.59 g (Yield 63%, m.p. 513-515 K).

Refinement
The amine H atom was located in a difference map and refined isotropically. The remaining H atoms were placed in calculated positions with d(C-H) = 0.93 Å, U iso = 1.2U eq (C) for aromatic and 0.97 Å, U iso = 1.2U eq (C) for CH 2 . The highest residual electron density peak is located at 0.58 Å from C18 and the deepest hole is located at 0.69 Å from C3. Fig. 1. The structure of (I), showing 50% probability displacement ellipsoids and the atomnumbering scheme.