p-Toluenesulfonic acid → 1-Cyclohexyl-6-(2-methoxycarbonyl-1-pyrrolyl)-7-nitro-2,3(1H,4H)-quinoxalinedione

Participants

Reaction Steps

10 g (33 mmol) of 6-amino-1-cyclohexyl-7-nitro-2,3(1H,4H)-quinoxalinedione (Example 28e), 6.9 g (36 mmol) of 2-methoxycarbonyl-2,5-dimethoxytetrahydrofuran and a spatula tip of p-toluenesulfonic acid were refluxed in a mixture of 50 ml of dimethylformamide and 50 ml of toluene with a water trap. After reaction was complete, the mixture was concentrated under reduced pressure, and the residue was treated with water. The precipitate was filtered off with suction to yield 11 g (79%) of the product. Melting point 211°-212° C.

Provenance & Evidence