Nitric Acid → HCID 13457930, compound

To a stirred solution of cis-1,3,4,6,7,11b-hexahydro-2-methyl-7-phenyl-2H-pyrazino[2,1-a]isoquinoline dihydrochloride (10.0 g, 0.0285 m) in trifluoroacetic acid (100 ml) maintained at 0° under nitrogen was added dropwise over a period of 30 minutes 90% nitric acid (25 ml). The mixture was stirred for 2 hours, then poured onto ice (1000 ml). Chloroform (200 ml) was added and the mixture basified to pH 11 with 50% NaOH. The layers were separated and the aqueous phase extracted with chloroform (2×200 ml). The combined chloroform extracts were washed with water (500 ml), dried over MgSO4, and evaporated to a yellow oil, 9.8 g. This was dissolved in methanol (200 ml), filtered, and the filtrate acidified with HCl gas. A white solid crystallized upon standing which was collected by filtration. This solid was recrystallized twice from methanol (200 ml) and water (10 ml) and vacuum dried at 95° for 24 hours to give 4.04 g of cis-1,3,4,6,7,11b-hexahydro-2-methyl-7-(4-nitrophenyl)-2H-pyrazino[2,1-a]isoquinoline dihydrochloride, m.p. 251°-252°.

1. additionpoured onto ice (1000 ml)
2. customThe layers were separated
3. extractionthe aqueous phase extracted with chloroform (2×200 ml)
4. washThe combined chloroform extracts were washed with water (500 ml)
5. dry with materialdried over MgSO4
6. customevaporated to a yellow oil, 9.8 g
7. dissolutionThis was dissolved in methanol (200 ml)
8. filtrationfiltered
9. customA white solid crystallized
10. filtrationwas collected by filtration
11. customThis solid was recrystallized twice from methanol (200 ml) and water (10 ml) and vacuum
12. customdried at 95° for 24 hours

ORD record

ord-72c3cea5a25f426fa2612dcb8da6dbe1

Source dataset

uspto-grants-1985_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04517187