Quinone → Methyl 1(7-chloroquinazolin-4-yl)-5-methoxy-2-methylindol-3-ylacetate

Participants

Reaction Steps

A solution of methyl 1-(7-chloroquinazolin-4-yl)-5-methoxy-2-methylindolin-3-ylacetate hydrochloride (2.15g.) in dry dimethylformamide (50ml.; dried with calcium hydride) was treated with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (1.2g.). The mixture was heated on a steam bath for 2 hours and then an additional portion of the benzoquinone derivative (0.6g.) was added. After further heating for 1 hour, the solution was poured into water (500ml.) containing anhydrous sodium acetate (10g.). The mixture was extracted with chloroform (3 × 100ml.) and the solid residue, at the solvent interface, discarded. The chloroform extracts were washed successively with water, saturated sodium bicarbonate solution, water and brine, and then dried (MgSO4). Evaporation of the solution gave an oil, which was purified by chromatography on silica gel (100g.) in an increasing gradient of ether in petroleum ether (b.p. 40°-60° C.) (polarity increased by incremental addition of 10% v/v ether) to give methyl 1-(7-chloroquinazolin-4-yl)-5-methoxy-2-methylindol-3-ylacetate as a yellow solid, m.p. 112°-114° C.

Provenance & Evidence