Hydrochloric Acid → 2-(4-Carboxyphenyl)-1-dimethylamino-4-phenyl-1-butene-3,4-dione

To a solution of 3-(4-carboxyphenyl)-1-phenyl-1,2-propanedione in 100 ml of dry dimethylformamide cooled in an ice-bath was added, with stirring, 56 ml of dimethylformamide dimethyl acetal. The reaction mixture was stirred at 0°-5° C. for 10 min. and then it was poured onto 1.2 l. of ice-water and acidified with 130 ml of 1N hydrochloric acid. After stirring for 5 min., 1.8 l. of water was added and the precipitate was collected, washed with water and air-dried. The filter cake was dissolved in 1.7 l. of methylene chloride, dried over anhydrous sodium sulfate, filtered and the filtrate was concentrated to about 200 ml. Ether (200 ml) was added and the solution was concentrated to about 300 ml and allowed to stand at room temperature for 2 days. The solid was collected, washed with methylene chloride-ether (1:9) and dried at 80° C. for 3 hrs. to give 17.4 g (44%) of 2-(4-carboxyphenyl)-1-dimethylamino-4-phenyl-1-butene-3,4-dione as yellow crystals, m.p. 208°-209° C.

1. additionwas added
2. stirringThe reaction mixture was stirred at 0°-5° C. for 10 min.
3. additionit was poured onto 1.2 l
4. stirringAfter stirring for 5 min.
5. customthe precipitate was collected
6. washwashed with water
7. customair-dried
8. dissolutionThe filter cake was dissolved in 1.7 l
9. dry with materialof methylene chloride, dried over anhydrous sodium sulfate
10. filtrationfiltered
11. concentrationthe filtrate was concentrated to about 200 ml
12. additionEther (200 ml) was added
13. concentrationthe solution was concentrated to about 300 ml
14. customThe solid was collected
15. washwashed with methylene chloride-ether (1:9)
16. customdried at 80° C. for 3 hrs

ORD record

ord-32bd1fc2bb0f4cd181dec7da60a7e83b

Source dataset

uspto-grants-1977_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04038289