Chlorofonn

The most powerful teclmique for studying VER in polyatomic molecules is the IR-Raman method. Initial IR-Raman studies of a few systems appeared more than 20 years ago [16], but recently the teclmique has taken on new life with newer ultrafast lasers such as Ti sapphire [39]. With more sensitive IR-Raman systems based on these lasers, it has become possible to monitor VER by probing virtually every vibration of a polyatomic molecule, as illustrated by recent studies of chlorofonn [40], acetonitrile [41, 42] (see example C3.5.6.6 below) and nitromethane [39, 43]. 

Chlorofonn, carbon tetrachloride, iodoform and the halogeno-benzenes do not give precipitates with cold aqueous silver nitrate solution. 

Addition occurs rapidly in a variety of solvents, including pentane, benzene, dichloro-inethane, chlorofonn, and acetic acid. 

This is called the haloform reaction because the trihalomethane produced is chlorofonn (CHCI3), bromofonn (CHBi ), or iodofonn (CHI3), depending on the halogen used. 

Chlorofonn is too non-polar to dissolve the phenolic compounds under study, but it dissolves many of the monoterpenes, at least to some extent. Because the solubility of some monoterpenes into chloroform was low, different solvent/ solid ratios were tested. These were 50,20,10 and 5 1/kg of dry phloem. The extracts were bright yellow and the strongest colour was with the smallest solvent/solid ratio (51/kg). The colour of the solvent indicated that the solubility of the extractable compounds was not restricting the reaction even with the smallest solvent volume. The taste of the dry samples was evaluated by comparing them to the original phloem sample. The results showed that the mildest taste was in the phloem extracted with a solvent/solid ratio of 50 1/kg and 20 1/kg also had some effect on the taste. The taste of the chloroform-extracted phloem was stabile and it was the same after a week. 

Procedure Weigh accurately benzalkonium chloride 4.0 g and dissolve it in sufficient DW to make 100 ml. Pipette 25.0 ml into a separating funnel, add 25 ml of chloroform, 10 ml of 0.1 N NaOH and 10 ml of potassium iodide solution. Shake the contents thoroughly, allow to separate and collect the chloroform layer in another separating funnel. Treat the aqueous layer with 3 further quantities each of 10 ml of chloroform and discard the chloroform layer. To the aqueous layer add 40 ml of hydrochloric acid, cool and titrate with 0.05 M potassium iodate till the solution becomes pale brown in colour. Add 2 ml of chloroform and continue the titration until the chlorofonn layer becomes colourless. Titrate a mixture of 29 ml of water, 10 ml of KI solution and 40 ml of hydrochloric acid with 0.05 M potassium iodate under identical conditions (Blank Titration). The differences between the titrations represent the amount of 0.05 M potassium iodate required. Each ml of 0.05 M potassium iodate is equivalent to 0.0354 g of C H CIN. 

NMR analysis, the PHA was extracted from freeze-dried cells. For this purpose, 1.0 g freeze-dried cells were stirred in 200 mL of chloroform for 24 hours at 30°C. The extract was filtered to remove cells debris, and the chloroform was concentrated to a volume of about 15 ruL using rotary evaporator. The concentrated solution was then added drop-wise to 150 luL of rapidly stirred methanol to precipitate the dissolved PHA.The precipitated PHA was then recovered by filtration using a 0.45 pm PTFE membrane and dried overnight at room temperature. The purified PHA was dissolved in deuterated chlorofonn (CDCl ) and subjected to H and NMR analyses. 

The formylation of a phenol 1 with chlorofonn in alkaline solution is called the Reimer-Tiemann reaction. It leads preferentially to formation of an ortho-formylated phenol—e.g. salicylic aldehyde 2 —while with other formylation reactions, e.g. the Gattermann reaction, the corresponding /jara-formyl derivative is obtained as a major product. The Reimer-Tiemann reaction is mainly used for the synthesis of o-hydroxy aromatic aldehydes. 

Silica gel GF254 Chlorofoim-methanol-benzene-aqueous 25% NH3 (90 5 5 1). Dichloromethane-pr( jan-2-ol-H20 (6 3 1) bulanol-lN ammonia (5 1). chlorofonn-acetone-aq. 25% ammonia (50 50 1). Five reagents 47... 

A suspension or solution of 0.20 mol of alkynyllithium in 140 ml of Et20 and 140 ml of hexane (see pag. 24) is cooled to -40"C and 6.4 g dry, powdered sulfur is added over 1 min. The cooling bath is removed and the temperature allowed to rise to 15-20 C. In all cases brown solutions are farmed. Stirring at 15-20 C is continued for about 1 h until all sulfur has dissolved. The solution is then transferred into the dropping funnel and added over 30 min to a mixture of 0.22 mol of freshly distilled acetyl bromide or 0.25 mol of ethyl chlorofonnate, and 200 ml of Et20. During, and for 30 min after this addition, the temperature of the mixture... 

Kugelrohr-Destillation des Riickstandes (0,13 g) bei 160-200° (Block-Temperatur)/0,005 Torr (0,67 Pa) und anschlieBende preparative Diinnschicht-Chromatographie an Aluminiumoxid (Chlorofonn/Ethyl-ace-tat) ergibt als erstes groBes Band 1. -Dibenzyl-2.31 -bipyrrolidinyl Ausbeute 60 mg (Ol). 

Methylbutyl Nitrite 3-Methylbutyraldehyde Methyl Carbitol Methyl Cellosolve Methyl Chloride Methyl Chlorocarbonate Methyl Chloroform Methyl Chlorofonnate... 

Substituting a diird chlorine on the methane molecule results in the compound whose proper name is trichloromediane (tri- for three chloro- for chlorine and methane, the hydrocarbon s name for die one-carbon chain). It is more commonly known as chloroform. Its molecular formula is CHC13. Chlorofonn is a heavy, colorless, volatile liquid with a sweet taste and characteristic odor. It is classified as non-flammable, but it will bum if exposed to high temperatures for long periods of time. It is narcotic by inhalation and toxic in high concentrations. It is an insecticide and a fumigant and is very useful in the manufacture of refrigerants. 

A 10% chlorofonn solution of 77.4% decaBDE (containing 21.8% nonaBDE and 0.8% octaBDE) or octaBDE did not induce bromacne when applied to tlie ear of rabbits for 30 days (Norris et al. 1975b). A... 

Habs, H., Kiinstler, K., Schmahl, D. Tomatis, L. (1983) Combined effects of fast neutron irradiation and subcutaneously applied carbon tetrachloride or chlorofonn in C57B1/6 mice. Cancer Lett., 20, 13-20... 

Solubility -. Insoluble in water slightly soluble in carbon tetrachloride miscible with chlorofonn, diethyl ether and ethanol (Budavari, 1996)... 

It is of interest to note that while chlorofonnic ester yields mostly the O-derivative, it is only the C-derivative that is obtained from chloro-acetic ester. 

On the other hand, chlorofonnic ester yields the C-derivative with cuproacetoacetic ester. (B., 37, 3394, 4627 38, 22.)... 

In 1996, the first successful combination of an enzymatic with a nonenzymatic transfomiation within a domino process was reported by Waldmann and coworkers [6]. These authors described a reaction in which functionalized bicy-clo[2.2.2]octenediones were produced by a tyrosinase (from Agaricus bisporus) -catalyzed oxidation of para-substituted phenols, followed by a Diels-Alder reaction with an alkene or enol ether as dienophile. Hence, treatment of phenols such as 8-1 and an electron-rich alkene 8-4 in chlorofonn with tyrosinase in the presence of oxygen led to the bicydic cydoadducts 8-5 and 8-6 in moderate to good yield (Scheme 8.1). It can be assumed that, in the first step, the phenol 8-1 is hydroxylated by tyrosinase, generating the catechol intermediate 8-2, which is then again oxidized enzy-... 

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