Acid chlorides functional group

Synthesis of new imide-containing monomers bearing amine or acid chloride functional groups starting from DPTA, followed by the reaction of the resultant monomers with the appropriate compounds [6-8]. 

The surface of silica particles has many exposed silanol —OH groups which are known to imdergo facile reaction with silanes contained —Si(OR), —Si(Cl), and —Si(H) units, and with acyl or sul-fonyl acid chloride functional groups [31,32]. Thus, preparation of the desired derivatized silica particles was easily accomplished by refluxing sihca in a nonhydroxyhc solvent with excess ti receptor reagents such as 3,5- or 2,4-dinitrobenzoyl or dinitrobenzenesulfonyl chloride. This... 

Each of the four acid chloride functional groups (C (= 0)CI) reacts with the amino (N H2) groups of amino acids, producing em amide. The labels of the substitutable positions are denoted by X, while Y, the substituents, is a set of amino acids. There are 20 pro-teinogenic a-amino acids, which eue all chiral except one (glycine). 

We recall that amides are best made by the reaction of acid chlorides and amines. Therefore, polyamides can be made by reaction of a monomer with two acid chloride functional groups and a monomer with two amine groups. However, the high reactivity of acid chlorides with nucleophiles such as water requires special precautions to preserve this reagent. Thus, these compounds are not much used in industrial laboratories. An alternate method for the synthesis of amides is the direct heating of an amine with a carboxylic acid. The first product is an ammonium salt, which loses water when heated to form the amide. 

The traditional method for transforming carboxylic acids into reactive acylating agents capable of converting alcohols to esters or amines to amides is by formation of the acyl chloride. Molecules devoid of acid-sensitive functional groups can be converted to acyl chlorides with thionyl chloride or phosphorus pentachloride. When milder conditions are necessary, the reaction of the acid or its sodium salt with oxalyl chloride provides the acyl chloride. When a salt is used, the reaction solution remains essentially neutral. 

This triiodinated synthon has an amino functional group (A) that is potentially reactive with the chloride functional groups of the acid (B). The amino functional group is protected in the form of a phthalimido group. 

For reasons which have already been described (Sect. 3.2.1) the synthesis of azo functions onto preformed polymers generally give poor results and are thus not common in the literature 22 -27). However, in a few cases it has proved possible to successfully introduce azo functions in this way. For example polymers having alcohol side groups have been esterified with azo compounds also containing an acid chloride function and the products used for grafting reactions 26) ... 

Acid chlorides also couple smoothly with lower-order zinc cyanocuprates (equation 59) to give ketones in high yields. Although most acid chloride substrates employed have been simple ones, alkenes, benzylic and alkyl chloride functional groups have been present in the acyl halide without incident25. 

Acid terminal groups in monolayers can be converted to a reactive acid chloride functionality simply by exposure of the monolayer to the vapours of thionyl chloride for a few minutes62,332. The formation of COC1 moieties was confirmed by IR spectroscopy. These functional groups can further react with amines or alcohols to produce amides and esters, which makes this method particularly useful for modification of alkanethiol mono-layers. However, the acid chloride-terminated monolayers are destroyed by solvents such as methylene chloride, and the reaction has to be performed in the gas phase332. 

Pyrido[2,3-(7]pyrimidincs 23, unsubstituted in the 2,4-positions, have been synthesized by condensation of ethyl 4-aminopyrimidine-5-carboxylate with several esters, phenylacetonitrile, phenylacetamide, or malonic ester chloride.173 In the first step, the 4-amino group reacts with the ester, nitrile, or acid chloride function of the cyclization partner, ring closure then being effected by a Dieckmann-type cyclization. 

Anionic polymerizations can be terminated by addition of another molecule, which will introduce an co-functional group in the chain. Excess carbon dioxide or cyclic anhydrides lead to terminal carboxylic groups, whereas addition of excess phosgene produces an acid chloride function. Similarly, isocyanates generate coamide functions, and lactones yield co-hydroxyl groups. 

An acid chloride functionalized liquid crystalline material was tried to bond to the silanol group in silica. The direct reaction does not seem to be successful also, a spacer with a substituted dichlorodimethyl silane is not successful. The reaction scheme is shown in Figure 16.8. However, a separation performance is observed rather by deposition than by bonding of the liquid crystals. The liquid crystalline materials used in this study was based on cholesteric moieties. It is suspected that the reaction failed because of the large size of the cholesteryl group. In another study, dimeth-ylchlorosilane was added to the allyl group of 4-methoxyphenyl-4-allyloxy benzoate. This intermediate could be bonded to silica. Several other routes to fix liquid crystalline moieties on silica have been reviewed. ... 

Dansyl chloride (DNS-Cl 5-dimethylaminonaphtha-lene-l-sulfonyl chloride) is used in analytical chemistry to fluorescently label substances. This process of dansyla-tion creates fluorescent derivatives, which can be detected with great sensitivity. The method for the dansylation of hydroxyl (-OH) and carboxylic acid (-COOH) functional groups has been described. Fluorescent labeling by dansyl chloride has applications in LC, HPLC, TLC, and MS. Fast TLC was accomplished using acetone as the resolving solvent, and resulted in good differentiation of analytes. 

Traditionally, concentrated HCl or HBr might have been used to convert alcohols to alkyl chlorides or bromides. The Appel reaction avoids the use of strong acids and thus can accommodate acid-sensitive functional groups. 

The reaction is mild enough to prevent epimerization of chiral intermediates (Scheme 11). mcio-Diesters can be converted to chiral acid esters. Conversion of the resultant acid chlorides 24 through 26, for example, to the aldehydes,provides useful chiral building blocks. The addition of 2,6-lutidine also helps when acid-sensitive functional groups are present such as the Boc protecting group of 27. ... 

The HeU-Volhard-Zelinsky reaction produces only bromocarbox-yhc acids. However, modified procedures have been developed to convert acyl chlorides into a-chloro- and a-bromoacyl chlorides by reaction with Wchloro- and Wbromobutanimide (N-chloro-and Af-bromosuccinimide, NCS and NBS Section 14-2), respectively. Reaction with I2 gives a-iodoacyl chlorides. (SOCI2 is used as the solvent to maintain the acyl chloride functional group.) Suggest a mechanism for any one of these processes. 

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