Hydrochloric Acid → 1-Methyl-5,6,7,8-tetrahydroisoquinoline

A solution of 1-methylisoquinoline (1.0 g) in methanol (30 ml) was saturated with gaseous hydrogen chloride at room temperature. The mixture was treated with platinum(IV) oxide (0.2 g). The mixture was vigorous stirred under hydrogen atmosphere at room temperature until hydrogen absorption was stopped. The reaction mixture was filtered off to remove the catalyst. The filtrate was concentrated in vacuo and the residue was taken up with water. The mixture was alkalized with sodium carbonate and the resultant precipitate was extracted with isopropyl ether. The extracts were dried over sodium sulfate, filtered and concentrated in vacuo to give 1-methyl-5,6,7,8-tetrahydroisoquinoline (1.03 g) as a brown oil. 1H NMR (CDCl3, δ): 1.6-2.0 (4H, m), 2.42 (3H, s), 2.5-2.9 (4H, m), 6.82 (1H, m), 8.16 (1H, m)

1. filtrationThe reaction mixture was filtered off
2. customto remove the catalyst
3. concentrationThe filtrate was concentrated in vacuo
4. extractionthe resultant precipitate was extracted with isopropyl ether
5. dry with materialThe extracts were dried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated in vacuo

ORD record

ord-a943148099ee43c3bf90ea8641e23146

Source dataset

uspto-grants-1998_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05763437