EtOH hydrogenation with

When strychnine is treated with hydrogen bromide and red phosphorus in boiling acetic acid, it is converted into a complex bromodeoxyiso-strychnine hydrobromide, (C2iH2iON2Br)a , which is hydrolysed by boiling N-sulphuric acid to isostrychnine (see above), now distinguished as I, and fsostrychnine-II, m.p. 218-9°, — 258° (EtOH), which with acetic... 

Bromide 133[80) (5.2 g, 13.9 mmol), adenine (5.07 g, 37.5 mmol), K2C03 (5.18 g, 7.5 mmol), and TBAI (0.5 g) were stirred in dry DMF (150 mL) for 24 h at rt. Water was added and the soln extracted several times with EtOAc. The organic layers were combined, dried (Na2S04), filtered, and concentrated to give crude 139, which was purified by flash chromatography (silica gel, EtOAc/EtOH 10 1) yield 3.84 g (65%). The latter was hydrogenated with 1 atm of H2 and Pd/C in EtOAc for 8h. The mixture was filtered on Celite, which was Soxhlet extracted with MeOH. The organic phases were combined and concentrated to afford 143 yield 45-65%. 

Compound 14 was hydrogenated with Pd/C as catalyst in 95% EtOH for 3 h. After filtration of the catalyst and concentration of the solvent under reduced pressure, compound 15 was quantitatively obtained as an oil yield 12.2 g (100%). 

The use of an acidic medium, in general, is favorable for the hydrogenation with any of the above catalysts. This is presumably connected with the elimination of the inhibitory effect of the amines formed during the hydrogenation. In imine hydrogenation reactions on Rh, five- to eightfold rate increases are observed when tartaric, phthalic, mandelic, salicylic or formic acids are added to the alcoholic reaction mixture (in a 95 5 mixture of EtOH-MeOH)447. 

The simultaneous removal of benzyl esters and benzyloxycarbonyl groups from peptides is accomphshed by catalytic hydrogenation with Hj, Pd/C in the usual organic solvents (e.g., EtOH, dioxane, DMF) at ambient temperatures (25-45 By employing catalytic... 

Methylpyrimidine-2,4.5-triamine (1.00 g, 7.00 mmol) was refluxed with a solution of glyoxal sodium hydrogen sulfite (2.24 g, 14 mmol) in H20 (22 mL) for 80 min. The hot solution was filtered, and the filtrate was cooled to yield a brown solid. This was washed with EtOH, shaken with 1 M NaOH (16 mL) for 30 min, then collected by filtration, washed with H20, and recrystallized (H20) to give 2 as yellow needles yield 0.35 g (23%) mp >290°C (dec.). 

Hydrogenation. With bis(dibenzotropyl)amine and a phosphine as coligands to modify [(cod)RhCl]2 a hydrogenation catalyst is formed. Reduction of alkenes and ketones with this system employs EtOH as hydrogen source. ... 

Potassium hydrogen malate [4675-64-3] M 172.2. A saturated aqueous solution at 60° was decolorised with activated charcoal, and filtered. The filtrate was cooled in water-ice bath and the salt was ppted by addition of EtOH. After being crystallised five times from ethanol-water mixtures, it was dried overnight at 130° in zir [Edenand Bales J Res Nat Bur Stand 62 161 1959],... 

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