反应详情

A catalyst consisting of palladium-on-carbon (3/97 by weight; 5 g) is added to a solution of 5-bromo-3-methyl-8-nitroisoquinoline (10.8 g) in ethanol (200 cc). The suspension is stirred, whilst heating to the reflux temperature under a nitrogen atmosphere, and hydrazine hydrate (25 cc) is added dropwise in the course of 30 minutes. The mixture is then heated under reflux for a further 2 hours. The suspension is filtered hot through diatomaceous silica and the filtrate is concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 40° C. The residue is dissolved in 0.5 N aqueous hydrochloric acid (200 cc) and the resulting solution is extracted with methylene chloride (2×50 cc). The aqueous phase is then rendered alkaline to pH 10 by addition of sodium hydroxide and is extracted with methylene chloride (3×150 cc). The organic extracts are combined, washed with water, dried over magnesium sulphate and filtered and the filtrate is concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 40° C. to yield 8-amino-3-methylisoquinoline (4.4 g), which is a beige solid, m.p.=175° C.

1. temperaturewhilst heating to the reflux temperature under a nitrogen atmosphere
2. temperatureThe mixture is then heated
3. temperatureunder reflux for a further 2 hours
4. filtrationThe suspension is filtered hot through diatomaceous silica
5. concentrationthe filtrate is concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 40° C
6. dissolutionThe residue is dissolved in 0.5 N aqueous hydrochloric acid (200 cc)
7. extractionthe resulting solution is extracted with methylene chloride (2×50 cc)
8. additionby addition of sodium hydroxide
9. extractionis extracted with methylene chloride (3×150 cc)
10. washwashed with water
11. dry with materialdried over magnesium sulphate
12. filtrationfiltered
13. concentrationthe filtrate is concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa) at 40° C.