No abstract

By YUSUF AHMAD, M. S. HABIB, M. IQBAL, and M. IKRAM QURESHI. THE rapid isomerisation of anilides (Ia-c) in concentrated sulphuric acid at 0" to the corresponding spiroindoles (IIa-c) has been attributedl to the presence of a strong electrophilic centre at position 2. However, the derivatives (Id-j) of 3,4-dihydro-6,7-dimet hoxy-(or 6,7-dimethyl-) -2-(N-phenylcarbamo yl) -3-oxoquinoxaline, when treated with cold concentrated sulphuric acid at room temperature, were recovered unchanged. This was expected as the presence of the electron-releasing substituents would make position 2 less electrophilic. The intramolecular rearrangement of the anilides (Ie-i and 111; R = Me) to the corresponding spiroindoles (IIe-i and IV; R = Me) was achieved Cl,H13N304 requires N, 15.9%).

The 6 km-thick, nonmarine Mt Daubeny Formation, commonly pale-red in colour, crops out in far western New South Wales. It is largely composed of arenite with subordinate siltstone and rudite. A basal orthoquartzite, the Koonburra Creek Quartzite Member, is present in the south whereas in the north three horizons (~ 0.5 km, 2.5 km and ~4.5 km above basement) contain andesite flows. The central part of the outcrop contains common 6m-thick orthoquartzite beds which are interbedded largely with pale-red or grey arenite and siltstone. The sequence containing orthoquartzite beds is at least 775m thick in che west and it is ~ 690m thick in the east where it is overlain by a ~610m sequence composed of brownred arenite and siltstone.The upper part of the formation is Early Devonian (Gedinnian) in age, is dated by fossil plants. The base of the formation is probably ~ 4 m.y. older than the fossiliferous horizon and this basal part may be latest Silurian in age. An unknown thickness of the formation has been removed by erosion since it was deposited.Palaeocurrents indicate that during the ?Latest Silurian-Early Devonian a mountainous terrain composed largely of Precambrian -? Cambrian rocks lay west of the present outcrop area of the formation area and provided the sediment from which the formation was formed.