Propane residual atmosphere

Propane Asphalt. As noted above, cmde oils contain different quantities of residuum (Fig. 2) and, hence, asphalt. Asphalt is also a product of the propane deasphalting and fractionation process (5,6,21,22) which involves the precipitation of asphalt from a residuum stock by treatment with propane under controlled conditions. The petroleum charge stock is usually atmospheric-reduced residue from a primary distillation tower. 

To a solution of 1.5 mmol of KDA, prepared from potassium lerl-butoxide, diisopropylamine and butyl-lithium, in 7 mL of diethyl ether is added dropwise, under an argon atmosphere, a solution of 0.293 g (1 mmol) of (/ )-2-methoxy-2-phenyl-l-[( )-3-phenyl-2-propenyloxy]propane in 2 mL of diethyl ether at — 100 °C (liquid nitrogen/methanol). After stirring for 5 h the resulting dark-red suspension is treated with a solution of 0.284 g (2 mmol) of iodomethane in 1 mL of diethyl ether. The mixture is stirred until the red color disappears (about 2 h). Then, the bath is removed and 5 mL of phosphate buffer (pH 7) are added, the mixture is extracted with ethyl acetate several times. The extracts are washed with aq NaCl, dried over MgS04, and concentrated. The residue is purified by TLC on silica gel to give (7 )-2-methoxy-2-phenyl-1-[(ii)-3-phenyl-l-butenyloxy]propane yield 0.232 g (75%). This is hydrolyzed to 3-phenylbutanal by treatment with aq perchloric acid (40 %)/diethyl ether. 

A mixture of 61 grams l-phenyl-l-oxo-2-(N-methyl-N-ethanolamino)-propane hydrochloride and 100 cc 98-100% formic acid was refluxed at the boiling point at atmospheric pressure for 45 minutes on an oil bath. Thereafter, the oil bath temperature was increased to 180°C and as much of the excess unreacted formic acid as possible was distilled off. A vigorous evolution of carbon dioxide developed during the distillation, which ceased after approximately 45 additional minutes. The honey-yellow syrup which remained as the distillation residue was worked up by admixing it with about six volumes of water and adjusting the aqueous mixture to alkaline reaction with concentrated sodium hydroxide. An oily phase separated out which was extracted with ether. The ether extract was washed with water and dried over potassium carbonate. The solvent was distilled off and the distillation residue was fractionally distilled in vacuo. The base boils at 132°-133°C at 12 mm. The yield was 93% of theory. Reaction with tartaric acid gave the final product. 

A solution of 31.0 g (0.42 mol) of glycidol in 85 ml of anhydrous benzene and 46.0 g of sodium carbonate is heated to reflux. At this temperature and under a nitrogen atmosphere a solution of 70.0 g (0.27 mol) of crude 2,6,2, 6 -tetramethylbenzhydryl chloride in 120 ml of anhydrous benzene is added drop-wise. After completion of the addition, the mixture is kept refluxing for another 8 h. After filtration and removal of the solvent under reduced pressure, the yellow coloured residue is subjected to distillation under reduced pressure. There are obtained 64.0 g (80% of the theoretical yield) of a fraction boiling at 175-195°C/1 mm Hg, which slowly solidifies. This distillate, consisting of crude l,2-epoxy-3-[di-(2,6-xylyl)-methoxy]propane, is used for the next reaction step without purification. 

Erythro- and Threo-2-( 1 -Hydroxybenzyl)cyclohexanones. A dichloro-methane (10 ml) solution of 1-trimethylsilyloxycyclohexene (0.426 g, 2.5 mmol) is added dropwise into a mixture of benzaldehyde (0.292 g, 2.75 mmol) and titanium(iv) chloride (0.55 g, 2.75 mmol) (2) in dry dichloro-methane (20 ml) under an argon atmosphere at — 78 °C, and the reaction mixture is stirred for 1 hour. After hydrolysis (with water) at that temperature, the resulting organic layer is extracted with ether, and the extract is washed with water and dried over anhydrous sodium sulphate. The extract is evaporated under reduced pressure, and the residue is purified by column chromatography (silica gel). Elution with dichoromethane affords 115 mg (23%) of eryt/jro-2-(r-hydroxybenzyl)cyclohexanone, m.p. 103 °C (recrystallised from propan-2-ol, m.p. 103.5-104.5 °C) i.r. 3530 (OH), 1700 (C=0)... 

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