Parr shaker

The checkers found the use of a Parr shaker (2 PSIG hydrogen, 16 hr, ambient temperatures) satisfactory for the hydrogenolysis step, and distillation (bp 108°C/2.5 mm, 89.9-91% yield) for purification. 

D. 4a(S),8a(R)-2-Benzoyloctahydro-6(2H)-isoquinolinone (4). Palladium (Pd), 10% on carbon, 4.0 g, (Note 21) is placed in a 500-mL Parr bottle under N2 and carefully wetted with 50 mL of cold denatured ethanol (EtOH). A slurry of 34.7 g of enone 3 (0.14 mol) in denatured EtOH (250 mL) is added and the Parr shaker apparatus assembled. After the system is purged with nitrogen-hydrogen (N2/H2), the reaction is shaken at 50 psi H2 and 50°C until H2 uptake is complete (1 hr, Note 22). The catalyst is filtered over a Celite pad (Note 23) and rinsed with warm chloroform (CHCI3) (4 x 75 mL). The filtrate is concentrated under reduced pressure, dissolved in 90 mL of CH2CI2 and crystallized with 200 mL of hexanes. The crystalline solid is filtered, rinsed with hexanes and dried to afford 34.3 g (98%, Note 24) of the ketone 4, representing a 51% yield over four steps. 

A 2.42 g (0.01 mole) of ethyl N-(p-cyanoethyl)indole-2-carboxylate is suspended in acetic anhydride (20 ml). The suspended compound is hydrogenated on a Parr shaker in the presence of Raney nickel. The uptake of hydrogen is complete after 1.5 h. The product recovered is recrystallized from benzene-hexane. The product obtained is ethyl l-(3-acetamidopropyl)indole-2-carboxylate, melting point 83.5°-84.5°C. 

To the 8 L of 1 1 methanol/water mixture containing the (Z)-2-carbomethoxy-3-phenyl-2-propene-l-sulfonic acid sodium salt was added 60.0 g of W-24 raney nickel. The resulting suspension was pressurized under 50 psi of hydrogen and was allowed to shake on a Parr shaker for 24 h, at which time an additional 20.0 g of raney nickel catalyst was added. After 6 h under 50 psi of hydrogen, the catalyst was removed by filtration and the solution was concentrated to dryness. To the dry white solid was added ethyl acetate (6 L) and heptane (4 L) and the solution was vigorously stirred with a mechanical stirrer overnight. The white suspension was removed by filtration yielding 530.0 g (88%) of the desired 2-carbomethoxy-3-phenylpropane-l-sulfonic acid sodium salt as an amorphous powder. 

These reductions were run in a Parr shaker in methanol at SS psi (absolute) at 25°C. 

PALLADIUM CATALYST, LIGANDLESS, 75, 61 20% Palladium hydroxide on carbon, 75, 21 Parr shaker, 75, 24, 226... 

Synthesis of l-(Benzylamino)imidazolidin-2-ones. Catalytic reduction of l-(benzylideneamino)imidazolidin-2-ones was only partially suc-cussful. For example, catalytic reduction over Pd-C with hydrogen in a Parr shaker gave l-(benzylamino)imidazolidin-2-one in low (32%)... 

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