Benzoyl chloride, reaction with amino

The or /io-positions of the benzene ring in 4,4-dimethyl-2-phenyl-4,5-dihydrooxazole 13, prepared from benzoyl chloride and the amino alcohol 12, are activated to such an extent that lithiation is possible. On reaction with an electrophile, e.g. a haloalkane, and followed by hydrolysis, 2-substituted or 2,6-disubstituted benzoic acids 14 or 15 are obtained [78] ... 

Another amino acid synthesis is called the azlactone synthesis. Remember from before that an azlactone is an oxazolone (see 95). When glycine (52) is converted to its AT-benzoyl derivative (112 known as hippuric acid) by reaction with benzoyl chloride, treatment with acetic anhydride (AC2O) gives the azlactone 113. This is the reaction presented in the preceding section (see compormd 95). Compound 110 has the common name of hippuric acid azlactone. As with the thiohydantoin, the -CH2- unit in 113 is susceptible to an enolate anion condensation reaction with aldehydes (Chapter 22, Section 22.7.2), and reaction with 2-methylpropanal in the presence of pyridine gives azlactone 114. Catalytic hydrogenation of the alkene unit (Chapter 19, Section 19.3.2) and acid hydrolysis lead to the amino acid leucine (55). 

B) Benzoyl derivatives. Most amino-acids can be benzoyl-ated when their solutions in 10% aqueous sodium hydroxide are shaken with a small excess of benzoyl chloride until a clear solution is obtained (Schotten-Baumann reaction, p. 243). Acidification of the solution then precipitates the benzoyl derivative and the excess of benzoic acid, and the mixture must be filtered off, washed with water, and recrystallised (usually from ethanol) to obtain the pure derivative. (M.ps., p. 555 )... 

The reaction of 6-benzoyl-3-amino-2-imino-2,3-dihydrothiazolo[4,5-A]quinoxaline 260 with benzoyl chloride cleanly affords the expected compound 371 in moderate yield (Equation 72) <2000PS(157)87>. 

Only one nonazapteridine (pyrimido[4,5- ]-l,2,4-triazine) derivative has been synthesized by the methods covered in this section. Thus, the reaction of the 5-amino-l,2,4-triazine-6-carboxylate 128a with triphenylphosphine/hexa-chloroethane produced the iminophosphorane 133 which underwent aza-Wittig reaction in hot benzoyl chloride in the presence of catalytic 4-dimethylaminopyridine (DMAP) to give the oxazino[6,5-< ]-l,2,4-triazine 134 as shown in Scheme 22 <2003ARK98>, which, as discussed in Section 10.20.1, constitutes an addition to the 44 ring systems covered by the remit of this chapter that were known at the time of CHEC-II(1996) <1996CHEC-II(7)785>. 

The properties and reactions of amino-alcohols, obtained largely by hydrolysis of naturally occurring alkaloids, were investigated primarily for the purposes of structural analysis and the preparation of physiologically active derivatives. Many authors have described acylation of pyrrolizidine alcohols with benzoyl chloride and acetic anhydride (see, e.g., refs. 83 and 101). Trachelanthamidine benzoate and p-aminobenzoate were prepared especially for testing of their physiological activity.102 The p-aminobenzoate was obtained by treatment of trachelanthamidine with p-nitrobenzoyl chloride and subsequent reduction of the nitro group with iron in 20% acetic acid. The compound exhibited an anesthetic activity close to that of cocaine. 

This synthesis involves Michael cycloaddition reaction of the readily available 4-hydroxycoumarine 1 with a cyanocrotonitrile 2 in ethanolic piperidine to afforded 2-amino-3-cyano-4-methyl-4H, 5H-pyrano-benzopyran-5-one (3). Treatment of 3 with acetic anhydride for 0.5 h and/or 3 h under reflux afforded N-acetyl and [l]benzopyrano[3/,4/ 5,6]pyrano(2,3-d) pyrimidine-6,8-dione derivatives (4) and (5a), respectively. Also, interaction of 3 with benzoyl chloride or formic acid gave the corresponding pyrimidine derivatives (5b,c) while its treatment with formamide afforded the aminopyrimi-dine derivative (6). 

Experiment 5.221 RESOLUTION OF dl-ALANINE Benzoyl DL-alanine. Dissolve lOOg (1.1 mol) of DL-alanine (Expt 5.180) in 400 ml of water containing 44.5 g (1.1 mol) of sodium hydroxide and cool the solution in an ice bath. Add 175g (1.2 mol) of benzoyl chloride and a solution of 49 g (1.2 mol) of sodium hydroxide in 200 ml of water to the stirred, cooled, amino acid solution, alternately and in portions during 2 hours continue to stir for a further 2-hour period. Boil the reaction mixture with 10 g of decolourising charcoal, filter, cool the clear yellow filtrate to 0 °C and acidify carefully to Congo red with concentrated hydrochloric acid. Triturate a portion of the oil which separates with water to induce crystallisation and then seed the bulk of the acidified solution with crystals and leave in an ice bath to complete the crystallisation process. Filter off the product, wash the filter cake with 500 ml of ice-cold water and recrystallise from about 3.5 litres of boiling water. The yield of benzoyl-DL-alanine, m.p. 162-164 °C, is 194.5 g (90%). 

Hydroxylamine supported on magnesia reacted, under microwave irradiation, with nitriles and benzoyl chlorides to afford in a one-pot reaction 1,2,4-oxadiazoles <07TL2829>. In a stepwise procedure, amino acids and dicarboxylic acids were transformed into the corresponding 3,5-disubstituted 1,2,4-oxadiazoles, useful as peptidomimetic building blocks <07TL1465>. 

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