4,4,8-trimethyl-1,3-dihydroquinolin-2-one

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: N-(1-oxo-3-methyl-but-2-en-yl)-2-methylaniline (0.5 g) was added with stirring to 98% w/w sulphuric acid (10 cm3) at 0°. After 2 hours at room temperature (20°) the mixture was poured carefully onto ice (30 g) and the resulting solution was basified to pH 9 with saturated carbonate solution. The mixture was then extracted wilth dichloromethane (2×200 cm3), and the combined and dried (MgSO4) organic extracts were evaporated in vacuo to give a solid which was chromatographed on silica (Merck "MK 60.9385" [Trade mark]). Elution with dichloromethane, followed by combination and evaporation of appropriate fractions gave the title compound, m.p. 120° (0.21 g). After 2 hours at room temperature (20°) the mixture was poured carefully onto ice (30 g) The mixture was then extracted wilth dichloromethane (2×200 cm3) dried (MgSO4) organic extracts were evaporated in vacuo to give a solid which was chromatographed on silica (Merck "MK 60.9385" [Trade mark]) Elution with dichloromethane followed by combination and evaporation of appropriate fractions

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of concentrated nitric acid (10 cm3, S.G.=1.42) and 98% w/w sulphuric acid (25 cm3) was added dropwise to a stirred solution of 3,4-dihydro-4,4,8-trimethyl-2-(1H)-quinolone (6 g) in 98% w/w sulphuric acid (25 cm3) cooled to -10°. The temperature was maintained at -10° for a further 30 minutes, the mixture poured onto ice (200 g), basified to pH 9 with saturated sodium carbonate solution and extracted with methanol:chloroform, 1:20 by volume (2×300 cm3). The combined and dried (MgSO4) organic extracts were evaporated in vacuo to give the title compound (6.46 g) which was characterised spectroscopically and used directly in Preparation 24 without further purification. cooled to -10° The temperature was maintained at -10° for a further 30 minutes the mixture poured onto ice (200 g) extracted with methanol dried (MgSO4) organic extracts were evaporated in vacuo