2-chlorophenyl

The nucleophilic reactivity of the oxygen has been observed in acetylation by acetic anhydride of 2-aryl- and 2-heteroaryl-A-2-thiazoline-4-ones (181) (388, 397, 410, 414, 416, 419, 422, 426. 427) and methylation of 5-(4 -chlorophenyl)-A-2-thiazoline-4-one (416) (Scheme 94). 

Loperamide. 4-(4-Chlorophenyl)-4-hydroxy-A7,A/-dimethyl- 7, 7-diphenyl-l piperidinebutanamide monohydrochloride [43552-83-5] (Imodium) (14) is practically iasoluble ia water (0.002%) at physiological pH. Its crystals are not affected by light and it is not hygroscopic. It may be synthesized (12). 

Solvent for Displacement Reactions. As the most polar of the common aprotic solvents, DMSO is a favored solvent for displacement reactions because of its high dielectric constant and because anions are less solvated in it (87). Rates for these reactions are sometimes a thousand times faster in DMSO than in alcohols. Suitable nucleophiles include acetyUde ion, alkoxide ion, hydroxide ion, azide ion, carbanions, carboxylate ions, cyanide ion, hahde ions, mercaptide ions, phenoxide ions, nitrite ions, and thiocyanate ions (31). Rates of displacement by amides or amines are also greater in DMSO than in alcohol or aqueous solutions. Dimethyl sulfoxide is used as the reaction solvent in the manufacture of high performance, polyaryl ether polymers by reaction of bis(4,4 -chlorophenyl) sulfone with the disodium salts of dihydroxyphenols, eg, bisphenol A or 4,4 -sulfonylbisphenol (88). These and related reactions are made more economical by efficient recycling of DMSO (89). Nucleophilic displacement of activated aromatic nitro groups with aryloxy anion in DMSO is a versatile and useful reaction for the synthesis of aromatic ethers and polyethers (90). 

An example of a sulfite ester made from thionyl chloride is the commercial iasecticide endosulfan [115-29-7]. A stepwise reaction of thionyl chloride with two different alcohols yields the commercial miticide, propaigite [2312-35-8] (189). Thionyl chloride also has appHcations as a co-reactant ia sulfonations and chlorosulfonations. A patent describes the use of thionyl chloride ia the preparation of a key iatermediate, bis(4-chlorophenyl) sulfone [80-07-9] which is used to make a commercial polysulfone engineering thermoplastic (see Polymers CONTAINING SULFUR, POLYSULFONe) (190). The sulfone group is derived from chlorosulfonic acid the thionyl chloride may be considered a co-reactant which removes water (see Sulfolanes and sulfones). 

BenZotrichloride Method. The central carbon atom of the dye is supphed by the trichloromethyl group from iJ-chlorobenzotrichloride. Both symmetrical and unsymmetrical triphenyhnethane dyes suitable for acryhc fibers are prepared by this method. 4-Chlorobenzotrichloride is condensed with excess chlorobenzene in the presence of a Lewis acid such as aluminium chloride to produce the intermediate aluminium chloride complex of 4,4, 4"-trichlorotriphenylmethyl chloride (18). Stepwise nucleophihc substitution of the chlorine atoms of this intermediate is achieved by successive reactions with different arylamines to give both symmetrical (51) and unsymmetrical dyes (52), eg, N-(2-chlorophenyl)-4-[(4-chlorophenyl) [4-[(3-methylphenyl)imino]-2,5-cyclohexadien-l-yhdene]methyl]benzenaminemonohydrochloride [85356-86-1J (19) from. w-toluidine and o-chloroaniline. 

C gH QN 5-(4-chlorophenyl)- Sanorex Sando2Wyeth-A 9] Q 2,5-dihydro-3JT-imi Ma2anor yerst... 

Oxazolo[4,5-6]pyridin-2(3 H)-one IR, 6, 653 <76HCA1593) Oxazolo[4,5-fi]pyridin-2(3H)-one, 3-(4-chlorophenyl)-3a,7a-dihydro-6-methyl-X-ray, 6, 647 <79CPB2261) Oxazolo[4,5-6]pyridin-2(3H)-one, 3-(4-chlorophenyl)-3a,7a-dihydro-7a-methyl-X-ray, 6, 647 <79CPB2261) 5H-Oxazolo[3,2-a]pyridin-3(2H)-one, 2-phenyl-6,7,8,8a-tetrahydro-X-ray, 6, 646 <77MI42902) Oxazolo[5,4-d]pyrimidin-4-amine, A7-methyl- H NMR, 6, 650 <70BCJ3909)... 

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