Benzoic acids diazotization

Toluene-benzoic acid process, of phenol manufacture, 18 750 Toluene diamine (TDA), 13 797 Toluenediamine (TDA), 25 189-201. See also Toluenediamines chain extenders for, 25 197 derivatives of, 25 196-197 diazotization of, 25 192 health and safety factors related to, 25 196... 

The thermal decomposition of diazotized anthranilic acid in acetone led to carbazole 328 as well as to 329, benzoic acid, and o-biphenylene. The 329... 

A photoreactive analogue, 2 -azidoAP (574ee) was prepared as shown in Scheme 3.120 [242], Intermediate (582) was synthesized from 2-nitro-4-amino-benzoic acid by protection of the amino group, reduction, diazotization and peptide coupling. 

Coupling, of benzenediazonium chloride with acetoacetic acid, 32, 84 of diazotized 3,5-dichloro-2-amino-benzoic acid to give 4,4, 6,6 -tetra-chlorodiphenic acid, 31, 96 of diphenyldichloromethane to tetra-phenylethylene, 31, 104 Crotonaldehyde, diethyl acetal, 32, 5 Cyanoacetamide, 32, 34 Cyanoacetic acid, 31, 25 -Cyanobenzaldehyde, 30, 100 3-Cyano-5,6-dimethyl-2(l)-pyridone,... 

Para-amino benzoic acid (PABA) can be measured by a diazotization reaction that yields a bright pink colour. The absorption is then measured at 510 nm. A series of standards yielded the results shown in Table 14.5. A graph of this data (Figure 14.11)... 

A neat intramolecular trap for benzyne works in this way. A standard benzyne-generating reaction—the diazotization of an ortho-amino benzoic acid (Chapter 23) gives a zwitterion that loses nitrogen and CO2 to release the benzyne. A furan tethered to the next ortho position traps the benzyne in an intramolecular Diels-Alder reaction. The yield is impressive and the trap is very efficient. 

Various preparations of antisera to atropine have been reported. A racemic hemisuccinate ester was prepared and conjugated to bovine serum albumin by the carbodiimide technique. Antisera formed to the original immunogen selectively bound the R isomer (34), but a later antiserum prepared by this approach was reported to bind both R and S forms with "equal efficiency" (35). R, S-atropine was treated with diazotized p-amino-benzoic acid, and the resulting compound (which was not further characterized) was used for conjugation to bovine serum albumin by means of a carbodiimide-mediated reaction. Antisera resulting from use of this material were quite selective for the R isomer, with a cross-reaction of only about 2% for the S isomer (36). Virtanen et al. followed this procedure with S-atropine. Their antiserum bound equally to S- and R,S-atropine, as measured by displacement of tritium-labeled R,S-atropine (37). In another study (31), both racemic atropine and the S isomer were coupled to human serum albumin by the technique of Wurtzburger et al. (36), Antisera were obtained that were selective for both the R and S isomers (33). 

Sharp regular edges are not always obtained. The diazotization of 4-amino-benzoic acid (7) on (101) with nitrogen dioxide (Scheme 2.1.3) is a typical example for a very large increase in the surface features upon the sudden phase transition that follows gradual phase rebuilding (Fig. 2.1.9). Preparatively, this is a waste-free quantitative synthesis of the solid diazonium nitrate 8 in a complicated multistep cascade reaction [9, 28]. 

It has been found by experiment that substances of the type RX, containing two different haptenic groups, do not form precipitates with either anti-R serum or anti-X serum Alone, but do form precipitates with a mixture of the two specific antisera. This provides proof of the effective bivalence of the dihaptenic precipitating antigen, and thus furnishes further evidence for e framework theory of antigen-antibody precipitation. In these experiments tiie anti-R serum and anti-X serum were made by injecting rabbits with sheep serum coupled with diazotized p-arsanilic add and diazotized p-aminobenzoic acid, respectively, and the RX substances used were l-amino-2-/>-(p-azophenylazo)-phenylarsonic acid-3,6-disul-fonic add 7-p-(p-azophenylazo)-benzoic acid-8-hy-droxynaphthalene and l,8-dihydroxy-2-/>-azo-phenylarsonic acid-3,6-disulfonic acid-7-p-(p-azo-phenylazo)-benzoic acid-naphthalene. 

Procedure. Urine (20 ml.) acidified with 2 N sulfuric acid (2 ml.) is continuously extracted with ether. The extract, after removal of the ether, is neutralized with 0.02 N sodium hydroxide uang phenol red as the indicator and is diluted so that concentration of p-hydroxybenzoic acid is between 0.2 and 2 mg./lOO ml. This solution (5 ml.) is mixed with ethanol (5 ml.) and diazotized p-nitro-anlline (1 ml.). After 2 minutes sodium carbonate (3 ml.) is added and the solution is made up to 25 ml. with water. The absorption is measured immediately on a photoelectric absorptiometer uang a Chance OBI blue filter. The calibration curve is constructed using solutions containing 0.01 to 0.10 mg. of p-hydroxy-benzoic acid in 5 ml. 

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