1-Chloro-3,6-dimethoxy-2,5-dimethylbenzene and 1-chloro-3,6-dimethoxy-2,4-dimethylbenzene.

The title compounds, 1-chloro-3,6-dimethoxy-2,5-dimethylbenzene, (IIIa), and 1-chloro-3,6-dimethoxy-2,4-dimethylbenzene, (IIIb), both C10H13ClO2, were obtained from 2,5- and 2,6-dimethyl-1,4-benzoquinone, respectively, and are intermediates in the synthesis of ammonium quinone derivatives. The isomers have different substituents around the methoxy groups and crystallize in different space groups. In both molecules, the methoxy groups each have different orientations with respect to the benzene ring.

2-Amino-4-(1-naphthyl)-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile and 2-amino-7,7-dimethyl-4-(1-naphthyl)-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile.

Syntheses and X-ray structural investigations have been carried out for the two title compounds, C(20)H(16)N(2)O(2), (IIIa), and C(22)H(20)N(2)O(2), (IIIb). In (IIIa), the heterocyclic ring adopts a sofa conformation, while in (IIIb), the ring has a flattened boat conformation. In both molecules, the fused cyclohexenone ring adopts a sofa conformation.

Bis(2,5-dimethoxy-4-methylphenyl)methane and bis(2,5-dimethoxy-3,4,6-trimethylphenyl)methane.

Bis(2,5-dimethoxy-4-methylphenyl)methane, C(19)H(24)O(4), (IIa), was obtained and characterized as a minor product from the reaction of toluhydroquinone dimethyl ether (1,4-dimethoxy-2-methylbenzene) with N-(hydroxymethyl)trifluoroacetamide. Similarly, bis(2,5-dimethoxy-3,4,6-trimethylphenyl)methane, C(23)H(32)O(4), (IIb), was prepared from the corresponding reaction of trimethylhydroquinone dimethyl ether (2,5-dimethoxy-1,3,4-trimethylbenzene). The molecules of (IIa) and (IIb) each lie on a twofold axis passing through the methylene group.