Triethylamine → 7-Chloro-3-[1-(6,7-dimethoxy-4-quinazolinyl)-4-piperidinyl]-1-ethyl-1,2,3,4-tetrahydro-6-nitro-2,4-dioxoquinazoline

Participants

Reaction Steps

The procedure similar to that described in Example 15 was repeated, except that 200.0 mg (0.47 mmol) of 7-chloro-3-(1-ethoxycarbonyl-4-piperidinyl)-1-ethyl-1,2,3,4-tetrahydro-6-nitro-2,4-dioxoquinazoline (Compound t) was used in place of Compound a, whereby 150.6 mg of crude 7-chloro-1-ethyl-1,2,3,4-tetrahydro-6-nitro-2,4-dioxo-3-(4-piperidinyl)-quinazoline hydrobromide was obtained. The product (145.0 mg, 0.31 mmol) was suspended in 10 ml of methanol, and 70 mg (0.31 mmol) of 4-chloro-6,7-dimethoxyquinazoline and 0.11 ml (0.78 mmol) of triethylamine were added thereto, followed by heating under reflux for 1 hour. After the reaction mixture was cooled to room temperature, water was added, and the precipitated crystals were collected by filtration, washed successively with water, methanol, and ether, and dried. Recrystallization of the resulting crude crystals from methanol/water gave 144.6 mg (yield from Compound t: 60%) of Compound 36 as pale yellow crystals.

Provenance & Evidence