Chlor methanes

Da C-Cl bzw. C-Br-Bindungen leichter hydrogenolytisch gespalten werden als die C—F-Bindung, erhalt man aus Difluor-dichlor-methan in organischen Losungsmitteln bei —70° neben Difluor-chlor-methan (29% d.Th.) Dimere (s. a. S. 667)1. 

Aus Difluor-dichlor-methan erhalt man in vcrschiedenen Elektrolytsystemen an einer amalgamierten Kup-fer-Elektrode bei —70° bei sehr gcringer Stromausbeute als Hauptprodukte Difluor-chlor-methan (29% d.Th.)... 

Das Hydrochloric von N(a)-Benzyloxycarbonyl-N jr)-benzyloxymethyl-histidin-methylester kann entweder aus iV( t)-Acetyl-N(tx)-benzyloxycarbonyl-histidin-methylester (R1 = CH, 88%) oder aus N(a)-Benzyloxycarbonyl-N(i)-tert.-butyloxycarbonyl-histidin-methylester [R1 = Q-C(CH3)3 48%] durch Umsetzung mit Benzyloxy-chlor-methan hergestellt werden883. 

Nitro-propen3 In einem Kolben werden 1,14 g (0,01 mol) Allyl-trimethyl-silan in 10 m/ trockenem Di-chlor-methan auf — 78° gekiihlt, innerhalb 20 min 1,33 g (0,001 mol) Nitronium-tetrafluoroborat zuge-geben. Man leitet einen schwachen Stickstoffstrom durch das GefaB um entstehendes Fluor-trimethyl-silan und Trifluor-boran abzufuhrcn. Nach 30 min ist alles Nitronium-Salz vcrschwunden. Man laBt auf 20° erwarmen, zieht das Dichlormethan ab und destilliert i.Vak. Ausbeute 0,7 g (80%) Sdp. 62°/25 Torr (3,25 kPa). 

Die Uberfuhrtmg von Halogen-alkanen mit Metallnitriten ist eine sehr haufig angewandte Methode. Man verwendet als Ration je nach Reaktion Silber, Natrium oder Kalium. Bei Benzyloxy-chlor-methan erreicht man die Nitrierung mit Silbernitrit die beste Ausbeute (25%)3. 

Powdered silver was found by Gomberg to yield results when sodium failed, in preparing the peculiar and interesting substance called by him triphenyl-methyl. Both triphenyl brom-methaue and triphenyl chlor-methane were used to effect the following change ... 

S-chlormethylestcr-O.O-diethylester XII/2, 667 aus Thiopliospliorsaure-0,0-diethylester (Am-moniuinsalz) und Brom-chlor-methan in Methanol XII/2, 653... 

SYNS ARTIC CHLOOR-METHAAN (DUTCH) CHLOR-METHAN (GERMAN) CHLOROMETHANE CHLORURE de METHYLE (FRENCH) CLOROMET-ANO (ITALIAN) CLORURO di METILE (ITALIAN) METHYLCHLORID (GERMAN) METYLU CHLOREK (POLISH) MONOCHLOROMETHANE R 40 RCRA WASTE NUMBER U045... 

Chlor methanes.—What now are these four new compounds and how do they throw light upon the nature of methane In the first place, all four of them have been isolated and their composition and formulas determined. They are called chlor-methanes and to distinguish them the number of chlorine atoms in the molecule is indicated by a numerical prefix, i.e.,... 

Mono-chlor methane Di-chlor methane Tri-chlor methane Tetra-chlor methane... 

Two of these compounds are well known substances, viz., tri-chlor methane, which is the valuable anaesthetic chloroform and tetra-... 

This means that methane is CH4, a saturated, symmetrical compound, in which carbon is tetra-valent, and all of the hydrogens are alike. It should be emphasized again that such a formula, which we call a structural or constitutional formula, does not represent the arrangement of the atoms in space, but is simply a plane representation of the most important facts in regard to methane as shown by definite reactions. The structural formulas for methane and the four chlor methanes are then as follows ... 

It is very important to grasp at the beginning the full significance and likewise the limitations of these structural formulas. To repeat the formula for mono-chlor methane, viz.,... 

When chlorine is substituted for hydrogen in methane and mono-chlor methane is obtained, we may assume as probable that one chlorine atom first removes hydrogen from the methane molecule, and then a second chlorine atom unites with the residue of methane. When one hydrogen is removed from methane we have left the residue (CH3—), i.e.j CH4 may be written CH3—H. In mono-chlor methane, then, the chlorine may be considered as united to the residue (CH3—) which as a group possesses the one valence of the carbon left unsatisfied by the one lost hydrogen. By our structural formulas we may represent the relations between methane and mono-chlor methane as... 

As in mono-chlor methane chlorine is thus represented as joined to the group (CH3—), so in all mono-substitution products of methane a monovalent element or group is joined to the monovalent group (CH3—). -A general formula, therefore, for all mono-substituted methanes may be written, CH3—X X being any mono-valent element or group. 

Mono-chlor methane CH3CI Methyl chloride Mono-brom methane CHsBr Methyl bromide Mono-iodo methane CH3I Methyl iodide... 

Methyl Chloride, Chlor-methane, CH3CI, is a gas, boiling at — 237°. It may be compressed in cylinders in which form it is used as a methylating reagent in the manufacture of dyes. It is also used for producing low temperatures and as a local anesthetic. 

Amino Compounds.—We have previously explained how mono-chlor methane, i.e,j methane in which one hydrogen atom has been substituted by a chlorine atom, may with equal justice be considered... 

Tests for Primary Amines.—The constitution of R—NC for the isocyanides is supported also by their synthesis from primary amines. When a primary amine, R—NH2, is treated with chloroform in alkaline solution an iso-cyanide is formed. Chloroform (p. 183), is tri-chlor methane, CHCI3. The reaction is. 

Relation to Methane and Acetic Acid.— The two syntheses of malonic acid which, prove its constitution also show its relation to methane and to acetic acid as indicated above. Di-cyano methane, which is made from di-chlor methane by the action of potassium cyanide, yields malonic acid on hydrolysis and on that account is also known as malonic nitrile. 

These compounds are exactly analogous to the four chlor methanes. 

By Friedel-Craft Reaction.—The best method of preparing the compound is by the Friedel-Craft reaction from benzene and benzyl chloride or by the same reaction from benzene and di-chlor methane. 

Synthesis.—This hydrocarbon is by far the most important of those in which two or more benzene rings are linked together by intervening aliphatic carbon groups. Just as methyl chloride and benzene by the Friedel-Craft reaction yield phenyl methane (methyl benzene or toluene) and methylene chloride, di-chlor methane, with benzene yields di-phenyl methane so by the same reaction tri-chlor methane, chloroform, yields with benzene a hydrocarbon which by this synthesis must be tri-phenyl methane. 

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