反应详情

50 ml of 2-amino-7-methoxyquinoline [C.A., Vol. 79, p. 92024t] were dissolved in 50 ml of dimethoxyethane and then a mixture of 3 g of ethyl bromopyruvate and 1 g of propylene oxide in 5 ml of dimethoxyethane was added thereto. The mixture was allowed to stand at 5° C. for 16 hours and the intermediate quaternary salt thus precipitated was filtered off, washed with diethyl ether and then was dissolved in 50 ml of ethanol. The solution was refluxed for 1 hour and then was reduced in volume under vacuum. Diethyl ether was subsequently added thereto to precipitate ethyl 8-methoxyimidazo-[1,2-a]-quinoline-2-carboxylate hydrobromide which was filtered off and was washed with diethyl ether. The hydrobromide was partitioned between 50 ml of dilute sodium carbonate solution and 100 ml of chloroform and the organic solution was separated, washed with 50 ml of water, was dried over MgSO4 and was evaporated to dryness under reduced pressure. The residue was crystallized from diethyl ether to obtain buff crystals of ethyl 8-methoxyimidazo-[1,2-a]-quinoline-2-carboxylate melting at 146°-148° C.

1. additionwas added
2. customthe intermediate quaternary salt thus precipitated
3. filtrationwas filtered off
4. washwashed with diethyl ether
5. dissolutionwas dissolved in 50 ml of ethanol
6. temperatureThe solution was refluxed for 1 hour
7. additionDiethyl ether was subsequently added
8. customto precipitate ethyl 8-methoxyimidazo-[1,2-a]-quinoline-2-carboxylate hydrobromide which
9. filtrationwas filtered off
10. washwas washed with diethyl ether
11. customThe hydrobromide was partitioned between 50 ml of dilute sodium carbonate solution and 100 ml of chloroform
12. customthe organic solution was separated
13. washwashed with 50 ml of water
14. dry with materialwas dried over MgSO4
15. customwas evaporated to dryness under reduced pressure
16. customThe residue was crystallized from diethyl ether