Hydrochloric Acid → HCID 21318665, compound

A 0.55 g. sample of N-(4,5,6,7-tetrahydro-4-oxobenzo[b]thien-7-yl)phthalimide is stirred and heated at reflux with 5 ml. of 6N HCl and one ml. of ethanol for 16 hours. Subsequently, the ethanol is distilled off and refluxing is continued for another 4 hours with the addition of 2 ml. of concentrated HCl. The mixture is cooled in ice, the white crystals of phthalic acid are filtered and washed with 5 ml. of water. The filtrate is washed with 15 ml. of CHCl3 and the aqueous solution of 4,5,6,7-tetrahydro-4-oxobenzo[b]thiophen-7-amine hydrochloride is neutralized until the solution is at pH 10-11 with 50% aqueous NaOH. The amine is then extracted from the aqueous mixture with chloroform (3×25 ml.). The combined extracts are dried over MgSO4 and evaporated to afford 0.17 g. of light yellow syrup. This gives the title compound with infrared absorption bands at 1660, 1620 and 1520 cm-1.

1. temperatureheated
2. temperatureat reflux with 5 ml
3. distillationSubsequently, the ethanol is distilled off
4. temperaturerefluxing
5. additionis continued for another 4 hours with the addition of 2 ml
6. temperatureThe mixture is cooled in ice
7. filtrationthe white crystals of phthalic acid are filtered
8. washwashed with 5 ml
9. washThe filtrate is washed with 15 ml
10. extractionThe amine is then extracted from the aqueous mixture with chloroform (3×25 ml.)
11. dry with materialThe combined extracts are dried over MgSO4
12. customevaporated
13. customto afford 0.17 g

ORD record

ord-1650b478c4e2431384b5346ddf58a7df

Source dataset

uspto-grants-1979_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04154740