Pentane as solvent

Initial attempts to stabilize A1C1 were carried out using pentane as solvent. The dark red condensate obtained at 77 K spontaneously turned black on warming above approximately 170 K due to the formation of aluminum as a result of disproportionation reaction (3 A1C1 2 Al + AICI3), and no subvalent Al species... 

The dependence of the counterion and of the solvent99 was studied in the addition of sec-butyl and tert-butyl mercaptide to methyl 4-bromocrotonate (3). The highest yield of the Michael addition induced cyclopropane product 10 was observed with lithium as counterion in dichloromethane or pentane as solvent. 

C02 of other monomeric stannilenes, such as bis[N-trimethylsilyl-N-2,6-diisopro-pylphenylamido]tin(II) and bis[N,N-bis(dimethylphenysilyl)amido]tin(II). Whilst the former stannilene was inert towards C02, the latter one underwent metathesis (323 K, 0.2 MPa, pentane as solvent) with the heterocumulene generating the relevant isocyanate and carbodiimide in a 4.4 1 molar ratio [117b]. 

Table 13. Reaction of me2(CH2Br)Si-C=C-SiHme2 119 with R2A1H (R = isobutyl) in presence of Lewis bases of different base strengths and with pentane as solvent...

Therefore, the production of the standard silaethene can only work well if the formation of the source by bromine/lithium exchange takes place faster than the thermal LiBr elimination. This is the case in diethyl ether, but not in pentane as solvent. 

New synthesis of heptamethyldisiiazane (2). The reaction of methylamine with trimcthylchlorosilane (I) using n-pentane as solvent gave (2) in 85 % yield. 

With respect to carbonylation chemistry Sakakura and Tanaka have shown that irridiation of rhodium complex RhCl(CO)(PMe3)2 in pentane as solvent under a CO atmosphere (1 bar) at ambient temperature gives rise to carbonylated products. Selectivity for linear aldehyde is > 98 % (eq. (11)) [45]. This insertion reaction is photochemically driven, since it is known that aldehyde decarbonylation is a thermodynamically favorable process. Other photochemial C-H activation reactions have been investigated [46]. When toluene is reacted in the presence of CO and the same Rh complex, phenyl acetaldehyde is obtained as the major product (eq. (12)) [47]. 

The commonly used method is the Soxhlet-Extraction by using diethylether and/or pentane as solvent. The sample is extracted continuously by using an Soxhlet-extrac-tor over a period of several hours. The extract is dried and concentrated by evaporation of the solvent. The residual extract can be applied directly to GC-analysis. This method is used for solid or pasty flavourings as well as for whole fruits or plants and their parts where the composition of the volatile compounds is required [4],... 

A mixture of 4,5-dimethyl-2-phenyl-2-phosphabicyclo[3.1.0]hex-3-ene 2-oxide (2.40 g, 11.1 mmol) and CljSiH (2.40 mL, 3.40 g, 25.0 mmol) in anhyd benzene (50 mL) was refluxed with stirring for 1.5 h. The mixture was then washed twice with 2 M NaOH and twice with HjO and dried (Na SOJ. The mixture was filtered under argon and the benzene was removed under vacuum. The product was purified by filtration through a 5 cm Florisil column, using degassed and argon-saturated pentane as solvent yield 1.70 g (75%). 

The aliiminuin imines are readily available by the addition of one equivalent of DIBAH to commercially available mandelonitrile and lactonitrile protected as t-butyl-dimethysilyl ethers in pentane at C. The use of pentane as solvent is important in order to get acceptable yields of aluminum imines lower yields in THF may be partially ascribed to a competitive reductive cleavage of the t-butyldimethylsilyl group. In situ treatment of the obtained aluminum imines with two equivalents of the organometallic compound at room temperature ftM 24 hours affords a mixture of syn and anti aminols. Lithium alkyls and allyl magnesium chloride have been used as nucleophiles. 

Chatot et al. [32] coupled thin layer chromatography with gas chromatography to determine PAHs. The hydrocarbons were separated by two-dimensional thin layer chromatography on prewashed cilumina-cellulose acetate (2 1), with pentane as solvent in the first direction and ethanol-toluene-water (17 4 4) as solvent in the second direction. Zones fluorescent under ultraviolet radiation were extracted with benzene, the extracts were evaporated, and a solution of each residue in benzene (20pL) was injected on to a stainless steel column (2m x 3mm) packed with 4.5% of SE-52 on Chromosorb G (DMCS). The carrier gas was nitrogen (60mL min ), the column was temperature programmed from 100 to 290°C at 3°C per minute, and detection was by flame ionisation. 

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