Hydrogenation Parr apparatus

L-(-)-7-benzyloxycarbonylamino-o -hydroxybutyrylI -6 -carbobenzoxykanamycin A was dissolved in 40 ml of 50% aqueous dioxane and a small amount of insoluble material was removed by filtration. To the filtrate was added 0.8 ml of glacial acetic acid and 1 gram of 10% palladium-on-charcoal and the mixture was hydrogenated at room temperature for 24 hours in a Parr hydrogenation apparatus. The reaction mixture was filtered to remove the palladium catalyst and the filtrate was evaporated to dryness in vacuo. 

The flask of a Parr hydrogenation apparatus was charged with 10,5 g of 3,3-diphenylpropyl-amine, 7.7 g of cyclohexylacetone, 50 ml methanol and 150 mg of platinum dioxide. Hydrogen at a pressure of 3 atmospheres was introduced and the mixture stirred. Upon absorption of the theoretical amount of hydrogen, stirring is discontinued, the catalyst is filtered off and the solution is evaporated to dryness. The residue is taken up with ether and the hydrochloride is precipitated with HCI in alcoholic solution. The product, as collected on a filter and washed with ether, is recrystallized from isopropanol. Yield 17 g (92.5% of theory). 

Examples Reaction mixtures include 10% Pd/C in THF—water at 50 psi H2 in a Parr hydrogenation apparatus for 1 hour,228 5% Pd/C in EtOH229 at... 

The flask of a Parr hydrogenation apparatus was charged with 10.5 g of 3,3-... 

If the hydrogenation is carried out in a Parr hydrogenation apparatus at 40-60 lb. pressure, about 2 hours is required to complete the hydrogenation as described. The low boiling point of the ethylenimine makes it impossible to remove the air from the bottle by evacuation in the usual way prior to hydrogenation. Instead the bottle is filled with hydrogen to 15-20 lb. pressure, the pressure is released, and the process repeated. 

The Parr hydrogenation apparatus shakes the reaction vessel (containing the alkene and the solid catalyst), while a pressurized cylinder supplies hydrogen. 

Transfer a solution of the /V,AA-dibenzyl-1,7,10,16,-tetraoxa-4,13-diazacy-clooctadecane (10 g, 0.023 mol) in ethanol (100 mL) to a 500 mL hydrogenation bottle suitable for use in a low pressure Parr hydrogenation apparatus. Carefully add Pearlman s catalyst (1.0 g), connect the bottle to the hydrogenation apparatus and shake for 72 h under a hydrogen pressure of 2-3 atmospheres. Filter the mixture through a bed of Celite (c. 1 cm) on a... 

A bottle for a Parr hydrogenation apparatus (A. H. Thomas Co., Philadelphia, Pa. 19105) is satisfactory, since the clamped rubber stopper fitting provides a seal adequate to hold 5 atmospheres pressure. 

Derivative 2 (27.6 g, 13 mmol) was dissolved in a mixture of absolute ethanol-CH2CI2 (4 1) (total 100 ml), 10% Pd-C (0.1 g) was added, and the mixture was hydrogenated overnight in a Parr hydrogenation apparatus at 50 p.s.i. [49]. The catalyst was removed by filtration, and the polymer was precipitated in diethyl ether and dried in vacuo to provide the corresponding amine (25.2 g, 12 mmol, 92%). The strong, characteristic IR absorption of azide (2110 cm ) that was present in the starting 2 was absent. 

Catalytic Hydrogenations. The hydrogenations were carried out with a Parr hydrogenation apparatus at room temperature and hydrogen pressures of about 35 psL Cyclohexene, cis-cyclooctene, or 1-hexene (0.1 ml) was added to 20 ml methanol. The catalysts were added either as a colloidal diversion or as a solid after evaporation of the solvent. An amoimt of catalyst corre onding to 1 wt% platinum (with rei ect to cyclohexene, cis-cyclooctene, or 1-hexene) was added. The reaction mixtures were analyzed by gas chromatography (SE-30 packed column) with a flbme ionization detector, and helium as a carrier gas. 

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