Hydrogen residual atmosphere

Reduction of 17a-EthynyI to 17a-Ethyl °° A solution of 5 g of 17a-ethynyl-androst-5-ene-3j9,17j5-diol in 170 ml of absolute alcohol is hydrogenated at atmospheric pressure and room temperature using 0.5 g of 5 % palladium-on-charcoal catalyst. Hydrogen absorption is complete in about 8 min with the absorption of 2 moles. After removal of the catalyst by filtration, the solvent is evaporated under reduced pressure and the residue is crystallized from ethyl acetate. Three crops of 17a-ethylandrost-5-ene-3) ,17j9-diol are obtained 3.05 g, mp 197-200° 1.59 g, mp 198.6-200.6° and 0.34 g, mp 196-199° (total yield 5.02 g, 90%). A sample prepared for analysis by recrystallization from ethyl acetate melts at 200.6-202.4° [aj, —70° (diox.). 

To a solution of 180 parts of -benzyl N-benzyloxycarbonyl-L-aspartvI-L-phenylalanine methyl ester in 3,000 parts by volume of 75% acetic acid is added 18 parts of palladium black metal catalyst, and the resulting mixture is shaken with hydrogen at atmospheric pressure and room temperature for about 12 hours. The catalyst is removed by filtration, and the solvent is distilled under reduced pressure to afford a solid residue, which is purified by re-crystallization from aqueous ethanol to yield L-aspartyl-L-phenylalanine methyl ester. It displays a double melting point at about 190°C and 245°-247°C. 

A solution of 1.7 g of 2-hydroxymethyl-3-benzyloxy-(1-hydroxy-2-tert-butyl-aminoethyl)py-ridine in 30 ml of methanol containing 1.2 ml of water is shaken with 700 mg of 5% palladium-onatmospheric pressure. In 17 minutes the theoretical amount of hydrogen has been consumed and the catalyst is filtered. Concentration of the filtrate under reduced pressure provides 1.4 g of the crude product as an oil. Ethanol (5 ml) Is added to the residual oil followed by 6 ml of 1.75N ethanolic hydrogen chloride solution and, finally, by 5 ml of Isopropyl ether. The precipitated product is filtered and washed with isopropyl ether containing 20% ethanol, 1.35 g, melting point 182 (dec.). 

The preliquefaction step did not appear to induce appreciable hydrogenation of the residue even with tetralin as a solvent or a hydrogen gas atmosphere. 

A solution of 3-(4-chloro-5-fluoropyrimidin-6-yl)-2-(2,4-difluorophenyl)-l-(lH-l,2,4-triazol-l-yl)butan-2-ol, enantiomeric pair B (0.307 g, 0.8 mmol) in ethanol (20 ml) was hydrogenated at atmospheric pressure and at room temperature in the presence of 10% palladium-on-charcoal (30 mg) and sodium acetate (0.082 g, 1 mmol). After 5 hours a further 10 mg of 10% palladium-on-charcoal was added and hydrogenation was continued for an additional 1 hour. The catalyst was removed by filtration and the filtrate was concentrated in vacuo. Flash chromatography of the residue on silica using 97 3 ethyl acetate/methanol as the eluent provided, after combination and evaporation of appropriate fractions and trituration with diethyl ether, the 2-(2,4-difluorophenyI)-3-(5-fluoropyrimidin-4-yl)-l-(lH-l,2,4-triazol-I-yl)butan-2-ol enantiomeric pair B, (0.249 g, 89%), m.p. 127°C. 

The removal of residual nitrate from UO was studied as a function of time and temperature under nitrogen, air and hydrogen-nitrogen atmospheres. The procedure used for these tests was to place a UO sample (lOg) in a vertical 2.54 cm diameter by 30.5 cm long stainless steel reactor, heat it to the desired temperature, and then start the gas flow. When the test was terminated, the sample was cooled and sampled for analysis. 

A-(m-2-Butenyl)phthalimide 283 A suspension of A-(2-butynyl)phthalimide (20 g) in ethyl acetate (1100 ml) is hydrogenated at atmospheric pressure in the presence of Lindlar catalyst (1 g) and quinoline (1 ml), until, after about 3.5 h, the consumption of hydrogen slackens (about 1.03 equivalents of hydrogen have been absorbed). The solution is filtered and concentrated in a vacuum. On recrystallization of the residue from 50% ethanol, N-(cis-2-butenyl)phthalimide (19.3 g, 96%) of m.p. 66-66.5° is obtained. 

Vanillin (3.04 g, 0.02 mol), dissolved in a minimum amount of absolute ethanol, was combined with 2.66 g of aminoacetaldehyde diethylacetal (0.02 mol), and the mixture was diluted to 15 mL with absolute ethanol and hydrogenated at atmospheric pressure and room temperature over 200 mg of previously reduced platinum oxide. Hydrogen consumption stopped at about 90% completion after about 3 h. The catalyst was removed by filtration and the solvent was evaporated under vacuum. The residual oil was dissolved in 50 mL concentrated hydrochloric acid. The solution which had become hot was cooled and washed with three 30-mL portions of 3 2 ether-benzene to remove starting aldehyde. A two-fold excess of benzaldehyde (4.24 g, 0.04 mole) dissolved in 50 mL of ethanol was added to the acidic solution which was subsequently boiled for 30 min. The cooled solution was diluted with an equal volume of water and washed with three 50-mL portions of ether to remove the excess benzaldehyde. The solution was made basic with ammonium hydroxide to pH 8. The precipitate was removed by filtration and crystallized once from water-ethanol to give 3.33 g of 4-benzyl-6-hydroxy-7-methoxyisoquinoline, in a yield of 63%, m.p. 185-190°C. The analytical sample has m.p. at 192-193°C. 

The conversion products, other than gas and hydrogen sulfide (H2S), are essentially a gasoline fraction that, after pretreatment, will be converted by catalytic reforming an average quality distillate fraction to be sent to the gas oil pool and an atmospheric residue or vacuum distillate and vacuum residue whose properties and impurity levels (S, N, Conr. 

Figure 2 illustrates the three-step MIBK process employed by Hibernia Scholven (83). This process is designed to permit the intermediate recovery of refined diacetone alcohol and mesityl oxide. In the first step acetone and dilute sodium hydroxide are fed continuously to a reactor at low temperature and with a reactor residence time of approximately one hour. The product is then stabilized with phosphoric acid and stripped of unreacted acetone to yield a cmde diacetone alcohol stream. More phosphoric acid is then added, and the diacetone alcohol dehydrated to mesityl oxide in a distillation column. Mesityl oxide is recovered overhead in this column and fed to a further distillation column where residual acetone is removed and recycled to yield a tails stream containing 98—99% mesityl oxide. The mesityl oxide is then hydrogenated to MIBK in a reactive distillation conducted at atmospheric pressure and 110°C. Simultaneous hydrogenation and rectification are achieved in a column fitted with a palladium catalyst bed, and yields of mesityl oxide to MIBK exceeding 96% are obtained. 

Purification. Tellurium can be purified by distillation at ambient pressure in a hydrogen atmosphere. However, because of its high boiling point, tellurium is also distilled at low pressures. Heavy metal (iron, tin, lead, antimony, and bismuth) impurities remain in the still residue, although selenium is effectively removed if hydrogen distillation is used (21). 

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