Hydrochloric Acid → HCID 53673182, compound

To a solution of 7.777 g (38.076 mM) of 5-thia-1,8b-diazaacenaphthylene-4-methanol in ethyl acetate (50 ml)-N,N-dimethylformamide (50 ml) was added 23 g of active manganese dioxide and the mixture was stirred at room temperature for 4 hours. The reaction mixture was filtered and the precipitate was washed with N,N-dimethylformamide. The pooled filtrate was distilled under reduced pressure to remove the solvent. The crude 5-thia-1,8b-diazaacenaphthylene-4-carbaldehyde thus obtained was not purified but used as it was in the next reaction. To a solution of 9.39 g (41.9 mM) of ethyl diethylphosphonoacetate in 50 ml of toluene was added 1.68 g (41.9 mM) of a 60% suspension of sodium hydride in liquid paraffin at room temperature and the mixture was stirred for 0.5 hour. This mixture was added to a solution of the above crude 5-thia-1,8b-diazaacenaphthylene-4-carbaldehyde in N,N-dimethylformamide (50 ml)-toluene (200 ml) under ice cooling and the mixture was stirred at room temperature for one hour. This reaction mixture was poured in water and extracted with 3 portions of ethyl acetate. The organic layers were pooled and dried over MgSO4 and the solvent was distilled off under reduced pressure. The resulting crude ethyl 3-(5-thia-1,8b-diazaacenaphthylen-4-yl)acrylate was not purified but used as it was in the next reaction. To a solution of the above crude ethyl 3-(5-thia-1,8b-diazaacenaphthylen-4-yl)acrylate in 300 ml of ethanol was added 60 ml (120 mM) of 2N-aqueous solution of sodium hydroxide and the mixture was stirred at room temperature for 3 hours. To this reaction mixture was added concentrated hydrochloric acid (ca 10 ml) with stirring to bring the pH into the range of 4-5 and the resulting precipitate was recovered by filtration and rinsed serially with ethanol and diethyl ether to provide the title compound.

1. customwas not purified
2. customwas in the next reaction
3. stirringthe mixture was stirred at room temperature for one hour
4. extractionextracted with 3 portions of ethyl acetate
5. dry with materialdried over MgSO4
6. distillationthe solvent was distilled off under reduced pressure
7. customThe resulting crude ethyl 3-(5-thia-1,8b-diazaacenaphthylen-4-yl)acrylate was not purified
8. customwas in the next reaction
9. stirringthe mixture was stirred at room temperature for 3 hours
10. stirringwith stirring
11. filtrationthe resulting precipitate was recovered by filtration
12. washrinsed serially with ethanol and diethyl ether

ORD record

ord-0d4be6f2c0bb43d5857cc4f850dc8728

Source dataset

uspto-grants-2001_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06235731B1