Yield:-

Reaction Conditions:

Stage #1: t-butoxycarbonylhydrazine;pentan-3-onewith acetic acid in ethanol at 80;
Stage #2: with hydrogen;palladium 10% on activated carbon in acetic acid; for 50 h;
Stage #3: with hydrogenchloride in water;ethyl acetate; for 5 h;

Steps:

158 Example 158

t-Butyl carbazate (1.32g), 3-pentanone (1.06 ml) and acetic acid (0.3 ml) are stirred overnight in ethanol (30 ml) at 80C. The solution is concentrated and dissolved in acetic acid (20 ml) and the mixture is stirred in the presence of 10% palladium carbon catalyst (0.5 g) under a hydrogen atmosphere for 50 hrs. The catalyst is filtered off and the mixture is washed with ethyl acetate. The solution is concentrated and dissolved in 4 Mol hydrochloric acid-ethyl acetate solution(10 ml). After stirring at room temperature for 5 hrs, the solution is concentrated to dryness to give 3-pentylhydrazine hydrochloride. A compound of Example 158 is synthesized from the obtained hydrazine hydrochloride according to a method similar to the method of Example 3. MS (ESI) m/z 237(M+H)+

References:

EP1396493,2004,A1 Location in patent:Page 41