Methylation benzoic acid

In an 800-ml. stainless-steel flanged beaker are placed 240 g. of potassium hydroxide pellets and 50 ml. of water. When the mush has cooled, 40.0 g. (0.263 mole) of 2-hydroxy-3-methyl-benzoic acid (Note 1) is added, and the slurry is stirred with a long glass rod. The beaker is placed firmly in a clamp (Note 2) and set in a cold oil bath (Note 3) in a hood, and 240 g. (1.00 mole) of lead dioxide is stirred in all at once (Note 4). The oil... 

These esters are prepared from the diazomethylpyrenes and carboxylic acids in DMF (R = H, 60% yield, R = Me, 80% yield, R = Ph, 20% yield for 4-methyl-benzoic acid). They are cleaved by photolysis at 340 nm (80-100% yield. R = H). The esters are very fluorescent. 

The aqueous phase was rendered acid with concentrated hydrochloric acid (weak Congo red and the separated acid taken up in ether. The isolated crude acid was recrystallized from dibutyl ether, yielding colorless crystals of 4-[(2-methvl-1,2-dicarbobenzoxy-hvdra-zino)-methyl] -benzoic acid, which melted at 112°C. The so-obtained product was sufficiently pure for further reaction. 

The solvents were then evaporated, y.ielding 4-[(2-methvl-1,2-dicarbobenzoxyhvdrazino)-methyl]-benzoic acid isopropylamide as a yellow oil, which crystallized upon triturating with ether MP 90°-92 C. This product was then covered with 70 ml of a 33% solution of hydrogen bromide in glacial acetic acid, and then permitted to stand for 2 hours with occas-... 

The macrocyclic ligands utilized for incorporation of copper generally contain four nitrogens separated by ethylene or propylene groups. The overall size of the macrocycle, thus, extends to fourteen atoms in the case of 4-[(l,4,8,ll-tetraazacyclotetradec-l-yl)methyl]benzoic acid (PCBA) (Figure 8).112... 

Fig. 6.46. El mass spectra of 2-hydroxy-acetophenone (a) and 2-methyl-benzoic acid (b). Spectra used by permission of NIST. NIST 2002.

Regioselectivity in the exchange of formally equal halogens can be found also outside the heterocyclic series. Inductive effects appear to be the controlling factor. For example, 3,3, 5-tribromodibenzyl ether (l,3-dibromo-5-[(3-bromophenyhnethoxy)methyl]benzene 5) is exclusively converted into 3-bromo-5-[(3-bromophenylmethoxy)methyl]benzoic acid (equation 3) when treated consecutively with butyUithium in tetrahydrofuran at —75 °C and dry ice. 

Synthesis of [n -(2-Methyl-benzoic acid 2-(2-methyl-acryloyloxy)-... 

SYNTHESIS OF [ -(2-METHYL-BENZOIC ACID 2-(2-METHYL-ACRYLOYLOXY)-ETHYL ESTER)RuCl2]2... 

Azidodi methyl benzoic Acid. See under Dj-methylbenzoic Acid and Beil 9, 538 Azidodimethyldinitrobenzene. See under Dimethylbenzene (Xylene) and Beil 5, 382 (188)... 

The benzene ring has been proposed as an isosteric replacement in a dipeptide to enforce either the tram l1 1 or the cis conformation 312>31 (Scheme 1). Similarly, 2-(amino-methyl)pyrrole-l-acetic acid (8, R = H) has been proposed as a cis peptide bond mimic,141 having the same number of atoms between the amino and carboxylic acid functions as in a dipeptide. Several other amino- and carboxy-substituted aromatic structures have been used as spacers in peptides 2-, 3-, and 4-aminobenzoic acids (Abz, e.g., 7), 2-, 3-, and 4-(amino-methyl)benzoic acids (Amb, e.g., 2), 2-, 3-, and 4-(aminophenyl)acetic acids (APha, e.g., 5), 2- (4), 3-, and 4-(aminomethylphenyl)acetic acid (Ampa), (aminomethyl)pyrrole-, -thiophene-, and -furancarboxylic acids 6, (aminomethyl)pyrrole- 8 and -thienylacetic acids, and aminobiphenylcarboxylic acids. 

Bis(trifluoromethyl)aniline on heating with sodium hydroxide gives 2-amino-4-(trifluoro-methyl)benzoic acid (4).170... 

Dinitro-2-chloro-4-methylaniline. (02N)2(Cl)CgH(NH2).CH3, yel nds(from ale), mp 173° was prepd by warming 3,5-dinitro-2 -chloro-4-methyl benzoic acid azide with AcOH Ref l,p [539] Ref 5) and... 

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