Sodium ethoxide → HCID 20534011, compound

1-[(4-Chloro-7-oxo-1,3,5-cycloheptatrien-1-yl)amino]-1,3-butanedione (480 mg) was suspended in a solution of sodium ethoxide (prepared from 46 mg of sodium and 2 ml of anhydrous ethanol). The solution was heated at reflux for 3 hr. The reaction mixture was cooled and filtered. The filtrate was evaporated to dryness. The residue was dissolved in water. The solution was rendered acidic with 6 N aqueous HCl. The precipitate was collected and dried to give 3-acetyl-6-chloro-1,2-dihydro-2-oxocyclohepta[b]pyrrole, nmr (DMSO-d6) δ2.55 (s, 3H), 7.3-7.95 (m, 3H), 8.9 (d, 1H). The latter compound (5.8 g) was added to a stirred solution of sodium hydride (77 mg, 50% suspension in mineral oil) and DMF (10 ml), the solution having been stirred at 25° C. for 30 min prior to the addition. Thereafter, ethyl bromoacetate (400 mg) was added to the mixture. The mixture was heated at 100°-105° C. for 1.5 hr, cooled, diluted with water and extracted with chloroform. The residue was purified by chromatography on silica gel using methylene chloride-ethyl acetate (9:1) as the eluant. The pure fractions were pooled to give 3-acetyl-6-chloro-1,2-dihydro-2-oxocyclohepta[b]pyrrole-1-acetic acid ethyl ester, nmr (CDCl3) δ1.3 (t, 3H), 2.7 (s, 3H), 4.2 (q, 2H), 4.85 (s, 2H), 7.6 (m, 4H).

1. temperatureThe solution was heated
2. temperatureat reflux for 3 hr
3. temperatureThe reaction mixture was cooled
4. filtrationfiltered
5. customThe filtrate was evaporated to dryness
6. dissolutionThe residue was dissolved in water
7. customThe precipitate was collected
8. customdried

ORD record

ord-4e1ea0b5fc474ab9a80bb3be0ea70d42

Source dataset

uspto-grants-1982_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04337265