C 2 catalyst

Fig. 2. LP Oxo gas recycle flow scheme A, feedstock pretreatment B, reactor C, catalyst preparation and treatment systems D, condenser E, separator F,...

Alternatively, butadiene can be oxidized in the presence of acetic acid to produce butenediol diacetate, a precursor to butanediol. The latter process has been commercialized (102—104). This reaction is performed in the Hquid phase at 80°C with a Pd—Te—C catalyst. A different catalyst system based on PdCl2(NCCgH )2 has been reported (105). Copper- (106) and rhodium- (107) based catalysts have also been studied. 

Chlorinated paraffins are manufactured by passing pure chlorine gas into a Hquid paraffin at a temperature between 80 and 100°C depending on the chain length of the paraffin feedstock. At these temperatures chlorination occurs exothermically and cooling is necessary to maintain the temperature at around 100°C. Catalysts are not usually necessary to initiate chlorination, but some manufacturers may assist the process with ultraviolet light. Failure to control... 

Fig. 6. Hydrogen hquefaction process. A represents adsorber C, catalyst bed HX, heat exchanger E, expander.

Hydrogenation of 2- (4-oxo-4//-pyrido[l, 2-n]pyrimidin-2-yl)oxymethyl -4-isopropyl-6-alkoxysaccharins 134 over 10% Pd/C catalyst at 50 psi Parr hydrogenator yielded 6,7,8,9-tetrahydro derivatives 135... 

Catalytic debenzylation of 10-(dibenzylamino)-6-(4-rerr-butylphenyl)-3,4-dihydro-2//-pyrimido[2,l-n]isoquinoline 421 (R = PhCH2) over a 5% Pd/C catalyst under hydrogen at atmospheric pressure in acidified EtOH at ambient temperature afforded the 10-amino derivative 421 (R = H) (98JMC1050). 

A different set of tautomeric tetrahydropyridines was obtained on partial hydrogenation of 2-alkoxy-3-acylpyridines 25 on PtOa or Pd/C catalyst (Scheme 9) (79JHC939). The tetrahydropyridines 26 formed exist exclusively as single tautomers, the type of tautomer, however, being determined by the substitution in the pyridine ring. 

Hydrogenation of 2,4u,5,6,7,8-hexahydropyrido[l,2-A][l,2]oxazin-8-onei 14 over 10% Pd/C catalyst gave perhydro derivatives 15 (96JCS(P1)1113, OOOL2955, 01JOC3338). 

Under the circumstance of catalytic hydrogenation of piperidine derivatives 190 in MeOH over Pd/C catalyst afforded an isomeric mixture of perhydropyrido[l,2-c]pyrimidines 174-177 (98TL7021, 00JA5017). The main product was 174 (66%). 

Reduction of 8-nitro-l,3,4,6,l 1,1 la-hexahydro[l,4]oxazino[4,3-/)]isoqui-nolin-4-one with BH3 in THF afforded 8-nitro-1,3,4,6,11,1 la-hexahydro [l,4]oxazino[4,3-/)]isoquinoline (97MIP4). Then the nitro group was reduced by catalytic hydrogenation over 5% Pd/C catalyst in acidified MeOH to yield 8-amino derivative. Catalytic hydrogenation of 3-nitro-6,6a,7,... 

A side-chain COOH group in 5//-pyrido[l,2,3- 7e]-l,4-benzoxazin-5-one was reduced into a HOCH2 group with NaBH4 in a 1 1 mixture of MeOH and THE at 5°C (98MIP13). Ethyl 7-oxo-2,3,6,7-tetrahydro-5//-pyr-ido[l,2,3- 7e]-l,4-benzoxazine-2-carboxylate was prepared by the catalytic hydrogenation of the l-oxo-5H derivative over 10% Pd/C catalysts in EtOH (99EUP894796). 

Oxo-2,3,6,7-tetrahydro-5//-pyrido[l,2,3- /e]-l,4-benzoxazine-2-carbox-ylates (291, X = H2) were obtained by hydrogenation of 4-substituted 3, 4-dihydro-2//-1,4-benzoxazine-2-carboxylates (290, X = H2) over 10% Pd/C catalyst, then by the treatment of free acids with (CF3C0)20 (99EUP894796). 5,7-Dioxo-2,3,6,7-tetrahydro derivatives 291 (X = 0) were prepared similarly from 290 (X = O). The products 291 (X = O) exist in 7-hydroxy-5-oxo-2,3-dihydro-5// tautomeric form. 

Methyl 2-substituted perhydropyrido[l,2-u]pyrazine-8-acetates were obtained by catalytic hydrogenation of 2-substituted 8-(methoxycarbonyl-methylene)perhydropyrido[l,2-a]pyrazines over 10% Pd/C catalysts (00JAP(K)00/86659). A side chain 4-pyridyl group was hydrogenated over Pt02 catalysts to yield a 4-piperidyl derivative. 

The side chain C=C double bond of 2,3,4,6,ll,lln-hexahydro-l//-pyrazino[l,2-i]isoquinoline-l,4-diones 354 was saturated by catalytic hydrogenation over Pd/C catalysts in EtOH to give 355 (98MIP7). 7-(2-Pyridylmethyl)amino derivative was obtained by reduction of 7-[(2-pyridylmethylene)amino]-2,3,11,11 n-tetrahydro-6//-pyrazino[l, 2-i]isoqui-noline-l,4-dione (356) with NaBH4 in EtOH at ambient temperature for 24 h. 

Substituted perhydropyrido[l,2-a]pyrazine-l,4-diones were obtained when methyl A-[2-(benzyloxycarbonylamino)acetyl]-4-substituted pipecoli-nates were hydrogenated over 10% Pd/C catalyst in MeOH, and then the methanolic solutions were refluxed (00JAP(K)00/86659). 

The. synthesis starts with the Stobbe condensation of diethylsuccinate and 3,4-dichloroben-zophenone (13). The product (14) is hydrolyzed and decarboxylated to a cis-trans mixture of olefins (15). This last is reduced using a Pd/C catalyst and then undergoes unidirectional Friedel-Crafts intramolecular acylation into the more reactive ring to produce substituted tetralone 16. 

A common consequence of migration in complex molecules is that tetrasubstituted olefins result, which can be hydrogenated only with difficulty, if at all. It is easier to try to prevent hindered olefin formation than it is to correct it. Attempted hydrogenation of the exocyclic methylene group in 15 proved difficult when using an aged 10% Pd-on-C catalyst there was a... 

Daily monitoring of API gravity provides the operator with a tool to predict changes in unit operation. For the same distillation range, the 26°API feed cracks more easily than the 24 API feed because the 26 API feed has more long-chain paraffinic molecules. In contact with the I, -100 F (704 C) catalyst, these molecules are easier to rupture into valuable products. 

Hydrocarbon A has the formula C9HI2 and absorbs 3 equivalents of H to yield B, C9H]g, when hydrogenated over a Pd/C catalyst. On treatment of A with aqueous H2S04 in the presence of mercury(d), two isomeric ketones, C and D, are produced. Oxidation of A with KMn04 gives a mixture of acetic acid (CH3C02H) and the tricarboxylic acid E. Propose structures for compounds A-D, and write the reactions. 

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