Chloroform CHCI

Problem 9.24 The carbene iCCl generated from chloroform, CHCI, and KOH in the presence of alkenes gives substituted cyclopropanes. Write the equation for the reaction of CClj and propene. <... 

When a base is used with a methy] ketone, the alpha carbon will become completely halogenated. This trihalo product reacts further with the base to produce a carboxylic acid and a haloform (chloroform, CHCI j bromoform, CHBr, or iodoform, CHIj). This is called the Haloform Reaction. 

When measured on a spectrometer operating at 200 MHz, chloroform (CHCI ) shows a single sharp absorption at /.3 6. 

CHLOROFORM CHCI, Tricbloroniethane Strong caostks. chemically active metak. such as aluminum, magnesium powder, sodium, potassium Not combosiiMe ... 

Dichlorocarbene (Cl C) can be made from chloroform (CHCy, and a strong base such as tert-butoxide, (CH l CO" or potassium hydroxide. Chloroform has three electron ative chlorine atoms, which inductively withdraw electron density from the carbon atom. Thus, the hydrogen atom of CHCI3 is much more acidic than the hydrogen atom of an alkane. The hase removes a proton from CHCI3, leaving the electron pair with the carbon atom. The product is a carhanion, the trichloro-methanide ion. 

If the four atoms attached to the central atom in a tetrahedral molecule are the same, as in tetrachloromethane (carbon tetrachloride), CCI4 (30), the dipole moments cancel and the molecule is nonpolar. However, if one or more of the atoms are replaced by different atoms, as in trichloromethane (chloroform), Cl ICI, or by lone pairs, as in NH3, then the dipole moments associated with the bonds are not all the same, so they do not cancel. Thus, the CHCI, molecule is polar (31). 

MIX 5 ml ETHANOL WITH 5 ml SODIUM HYPOCHLORITE SOLUTION ("CLO-ROX"). HEAT MIXTURE GENTLY FOR A FEW MOMENTS WITHOUT 801 LING. THEN SNIFF CAREFULLY. YOU GET THE PECULIAR SWEETISH ODOR OF CHLOROFORM. THE C,HsOH HAS BEEN TURNED INTO CHCI,. 

To a THF (15 mL) soln of (l-pyrenyl)methanol (3.07 g, 13.2 mmol) and 4-nitrophenyl chloroformate (3.21 g, 16.0 mmol), pyridine (1.3 mL) was added dropwise at 0 °C. The mixture was stirred at 0 °C for 1 h and then at rt for 2 h. The solvent was distilled off and the residue dissolved in CH2C12, washed successively with 1M HC1, 4% NaHC03, H20, and sat. NaCl, then dried (Na2S04). After removal of the solvent, recrystallization of the crude product from CHCI s/hexanes gave 4-nitrophenyl 1-pyrenylmethyl carbonate yield 4.79 g (91%) mp 130 °C. 

The high-yield dealkylation with ACE-CI is therefore very surprising. Presumably, the -CHCI-CH3 unit is too hindered to undergo competitive SN2 attack by O and the 1-chloroethyl cation generated by an alternative SN., (E.,) cleavage must be too unstable. Because the substituent is electron withdrawing, ACE-CI is more reactive toward tertiary amines than simple alkyl chloroformates. 

Oxidation [1, 391, after citation of ref. 9a], Ferric chloride (1 N) in a 1 1 two-phase system with chloroform oxidizes (1), the trifluoroacetate of methoxy-O-methylnorbelladine, to the dienone (2) in 12% yield. The product (2) on hydrolysis with 2 N Na.CO ,-CHCI l undergoes a second intramolecular condensation to give the ring system of the crinine alkaloids, (3). Jb... 

If a mixture of ethanol and water is distilled, eventually it will form a solution that is 95 % ethanol regardless of the starting composition. Hydrochloric acid and water will form a 20.22 % HCl solution, and chloroform and acetone will form a 65.5 % CHCI, solution. These solutions are called azeotropes (Gr a + zeo to boil, trope more at). Webster s dictionary defines an azeotrope as a liquid mixture that is characterized by a constant maximum or minimum boiling point which is lower or higher than that of any of the components and that distills without change in composition. An azeotropic distillation involves the formation of an azeotrope with at least one of the components of a liquid mixture, which then can be separated more readily because of the resulting increase in the difference between the volatilities of the components of the mixture. Figure 4-1, p. 44, shows the water-ethanol system (A) and the HCl-water system (B). 

Iodine-chloroform reagent (I/CHCy 0.5% Iodine in chloroform. 

Crystals from ethyl acetate, mp 184" (Lewenstein), 177-178 (Sankyo Co ). Mg -194.5" (c = 0.93 in CHCI,). Sol in chloroform. Practically insol in petr ether. 

Needles from alcohol, mp 221-222. [< ] -1-96.3 (CHCy. Very sol in alcohol, ether, petr ether slightly sol in chloroform, benzene, carbon disulfide, acetone. 

C20H24N2O2, Mr 324.42 cryst. bitter substance, mp. 177 °C (as trihydrate mp. 57 °C), [a]o - 117° (CHCI,), Q. is a quinoline alkaloid, poorly soluble in water, readily soluble in organic solvents (alcohol, chloroform). It dissolves in oxygen-containing acids with a blue fluorescence like quinidine. Like other Cinchona alkaloids Q. forms soluble salts in plants, especially with quinic acid and tannins, e.g., as quinine citrate. The sulfate and hydrochloride of Q. are used in therapy. Q. is also used in racemate separations. "Quini-... 

Table 1.12). This amount can be significantly lower than that dissolved in chloroform because AGs h o->chci H o cci Now initial and MCA silicas are compared to elucidate the textural... 

Synonyms 1.3-Dichloropiopene Telone Chemical Formula CICHjCn CHCI (ii) Observable Characteristics — Physical State (as normally shipped) Liquid Cotar Colorless Odor Sweet like chloroform (iii) Physical and Chemical Properties — Physical State at 15 C and I atm. Liquid Molecular Weight 110.98 BdUng Point at I atm. 170, 77, 350 Freezing Point Not pertinent Critical Temperature Not pertinent Critical Pressure Not pertinent ecific Gravity 1.2 at 20 C (liquid) Vapor (Gas) Density Not pertinem Ratio of Specific Heats of Vapor (Gas) 1.116 Latent Heat of Vaporization 113. 

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