Acid chlorides, preparation from acids

To 1 gramm-equivalent (g-eq) of dimethylaminoethanethiol in 150 ml of ether, a suspension of g-eq of 50% sodium hydride in 50-ml of anhydrous ether was added. After boiling for 1 hour, the reaction mixture was cooled to 0°C, whereupon g-eq of 9,9-dimethylacridan-10-carboxylic acid chloride (prepared from 9,9-dimethylacridan and phosghene - cf. Swiss Specification No. 

From the acid chloride (prepared from the acid and thionyl chloride) and aniline in benzene or in ether For directions and examples see Cheronis, p 445, Linstead, p 14, Shrmer, pp 98, 200-1, Vogel, pp 361, 369, 458, Wild, p 182, P W Robertson, y Chem Soc, 115, 1210 (1919)... 

A soln. of vitamin A acid chloride (prepared from the acid and PC/g) in dioxane added dropwise during 10 min. at 10° to a vigorously stirred soln. of Na-retinoyl-hydroxamate prepared by addition of aq. NaOH to the hydroxamic acid in dioxane, and stirred 3 hrs. at 20° in a closed flask in the dark N,0-diretinoyl-hydroxylamine. Overall Y 73.4%. R. Miller, Chim. Therap. 9, 298 (1974). 

J13,17a-l7.Keto-D-homosteroids. Anhydrous Cd-chloride added portion wise to methylmagnesium bromide from methyl bromide and Mg-turnings in ether, refluxed 2 hrs., filtered under Ng, the efficiently stirred filtrate treated drop-wise with Jf>13(18)-3-keto-13,17-seco-androstadien-17-ic acid chloride (prepared from 550 mg. acid and oxalyl chloride), and refluxed 2 hrs. 250mg. J4,l3(l7a). 3,17-diketo-18-nor-D-homoandrostadiene. F. e. s. H. Heusser et al., Helv. 42, 2140 (1959). 

Startg. acid chloride (prepared from the acid with oxalyl chloride) allowed to react at -15° with SnGl4 in GSg product. Y 84%. R. R. Sobti and S. Dev, Tetrah. Let. 1967, 2893. 

Other Rea.ctlons, The anhydride of neopentanoic acid, neopentanoyl anhydride [1538-75-6] can be made by the reaction of neopentanoic acid with acetic anhydride (25). The reaction of neopentanoic acid with acetone using various catalysts, such as titanium dioxide (26) or 2irconium oxide (27), gives 3,3-dimethyl-2-butanone [75-97-8] commonly referred to as pinacolone. Other routes to pinacolone include the reaction of pivaloyl chloride [3282-30-2] with Grignard reagents (28) and the condensation of neopentanoic acid with acetic acid using a rare-earth oxide catalyst (29). Amides of neopentanoic acid can be prepared direcdy from the acid, from the acid chloride, or from esters, using primary or secondary amines. 

Because of the structural requirements of the bielectrophile, fully aromatized heterocycles are usually not readily available by this procedure. The dithiocarbamate (159) reacted with oxalyl chloride to give the substituted thiazolidine-4,5-dione (160) (see Chapter 4.19), and the same reagent reacted with iV-alkylbenzamidine (161) at 100-140 °C to give the 1 -alkyl-2-phenylimidazole-4,5-dione (162) (see Chapter 4.08). Iminochlorides of oxalic acid also react with iV,iV-disubstituted thioureas in this case the 2-dialkylaminothiazolidine-2,4-dione bis-imides are obtained. Thiobenzamide generally forms linear adducts, but 2-thiazolines will form under suitable conditions (70TL3781). Phenyliminooxalic acid dichloride, prepared from oxalic acid, phosphorus pentachloride and aniline in benzene, likewise yielded thiazolidine derivatives on reaction with thioureas (71KGS471). 

Chlorophenylacetic acid [1878-65-5] M 170.6, m 74°, pK 4.11. Crystd from EtOH/water, or as needles from C6H6 or H2O (charcoal). The acid chloride (prepared by boiling with SOCI2) has b 127-129°/15mm. [Dippy and Williams J Chem Soc 161 1934 Misra and Shukla J Indian Chem Soc 28 480 1951.]... 

Carboxylic acids, a-bromination of 55, 31 CARBOXYLIC ACID CHLORIDES, ketones from, 55, 122 CARBYLAMINE REACTION, 55, 96 Ceric ammonium nitrate [Ammonium hexa mtrocerate(IV)[, 55, 43 Chlorine, 55, 33, 35, 63 CHROMIUM TRIOXIDE-PYRIDINE COMPLEX, preparation in situ, 55, 84 Cinnamomtnle, a-phenyl- [2-Propeneni-tnle 2,3-diphenyl-], 55, 92 Copper(l) iodide, 55, 105, 123, 124 Copper thiophenoxide [Benzenethiol, copper(I) salt], 55, 123 CYCLIZATION, free radical, 55, 57 CYCLOBUTADIENE, 55, 43 Cyclobutadieneiron tricarbonyl [Iron, tn-carbonyl(r)4-l,3-cyclo-butadiene)-], 55,43... 

Amino acids activated at the amino group by a benzotriazolide moiety react with amino acids under elimination of benzotriazole and C02 to give peptides. Reaction is achieved by warming up equimolar amounts of the components in anhydrous acetonitrile or aqueous acetone.[45] The benzotriazolylcarbonylamino acids are prepared from benzo-triazolyl-1-carboxylic acid chloride and amino acids.[46]... 

Another -activation of amino acids for peptide synthesis is achieved by preparing sulfenamides from sulfenylimidazoles. A sulfenylimidazole is formed in situ from the sulfenyl chloride (prepared from the disulfide and chlorine) and imidazole, which reacts further with an amino acid ester to give a sulfenamide in high yield. Conversion of such sulfenamides with IV-acyl amino acids by means of triphenylphosphine affords dipeptides with racemization of less than 0.5%.[481... 

The required phosphorimidazolides are prepared from acid chlorides and imidazole or Af-trimethylsilylimidazole. 

The 977-pyrido[3,4- ]pyrrolizin-9-one 145 has been prepared for its photochemical properties. The preparation involves an intramolecular Friedel-Crafts acylation of the acid chloride formed from 3-(l-pyrrolyl)pyridine-4-carboxy-late (Scheme 40). The product is a photosensitizer, which absorbs visible light its absorption spectra are pH, solvent, and concentration dependent <1994SAA57>. 

High antiscorbutic power is also reported to be shown by a derivative of L-ascorbic acid in which the enolic hydroxyl group at C2 is replaced by an amino group. 3,4-Isopropylidene-L-threonic acid (LX), prepared from 5,6-isopropylidene-L-ascorbic acid, is converted into the 2-acetyl-3,4-isopropylidene-L-threonyl chloride (LXI) and this is then allowed to react with the sodium derivative of ethyl malonate. 

Interestingly, the Fischer indole synthesis does not easily proceed from acetaldehyde to afford indole. Usually, indole-2-carboxylic acid is prepared from phenylhydrazine with a pyruvate ester followed by hydrolysis. Traditional methods for decarboxylation of indole-2-carboxylic acid to form indole are not environmentally benign. They include pyrolysis or heating with copper-bronze powder, copper(I) chloride, copper chromite, copper acetate or copper(II) oxide, in for example, heat-transfer oils, glycerol, quinoline or 2-benzylpyridine. Decomposition of the product during lengthy thermolysis or purification affects the yields. 

Nitronate(47a) is not the only oxazete derivative. For example, sterically hindered nitroalkenes (42b-d) can be prepared by nitration and halogenation of readily available allenes (48). Compounds (42b-d) are rather smoothly isomerized into the corresponding four-membered cyclic nitronates (47b-d) by the first-order reaction equation (168). Storage of nitronate (47c) is accompanied by its slow transformation into acid chloride (47e) from which amide (47f) can be easily synthesized. 

Aqui et al. investigated the cyclization of diethyl A-(3-substituted phe-nyl)aminomethylenemalonates (251) under different cyclization conditions (75JHC557). For cyclization, they applied a 4 7 mixture of concentrated sulfuric acid and acetic anhydride, polyphosphoric acid, polyphosphate (prepared from phosphorus pentoxide and diethyl ether in chloroform), phosphoryl chloride, and Dowtherm A (see Table VI). They found the most effective cyclization conditions were thermal cyclization (heating in Dowtherm A) and polyphosphate. 

The heterocyclic acylphosphines (52) and (53) have been prepared by the reaction of phenylbis(trimethylsilyl)phosphine with the acid chlorides derived from phthalic and diphenic acids. The reaction of 2,3-dichloromaleic anhydride or thioanhydride with phenylbis(trimethylsilyl)phosphine gives derivatives of the 1,4-dihydro-p-diphosphorin system (54).45... 

The acid chloride or the acid may be purchased from Aldrich Chemical Company, Inc. The acid chloride must be pure (99% minimum by gas chromatography analysis) whether purchased or prepared. Purification was effected by recrystallization from Skellysolve B. 

H20)2C1]S04, exists in two modifications, a blue-green modification and a violet form., It is prepared from acid dichloro-aquo-triammino-eobaltie sulphate, [Co(NH3)3(H2Q)C12]S04H, by treating a saturated aqueous solution with an equal volume of alcohol. The precipitate of green-coloured salt is collected and dried over sulphuric acid. It separates as a fine crystalline powder, and if crystallised from an aqueous solution is gradually transformed into the isomeric violet salt. Concentrated hydrochloric acid precipitates from the aqueous solution dichloro-aquo-tetrammino-cobaltie chloride. 

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