Selectivity in tosylation of p-aminophenol was written by Kurita, Keisuke. And the article was included in Chemistry & Industry (London, United Kingdom) in 1982.SDS of cas: 1146-43-6 This article mentions the following:
Tolylsulfonylation of p-H2NC6H4OH with p-MeC6H4SO2Cl in CH2Cl2 containing Et3N at 25° for 2 h gave 81% p-MeC6H4SO3C6H4NH2–p (I), 6% p-MeC6H4SO3C6H4(NHO3SC6H4Me-p)-p (II), and 4% p-HOC6H4NHO3SC6H4Me-p (III). With Me3COK as base only 32% I was obtained. When pyridine was used III was the major product (76%), only 1 and 14% of I and II, resp., being obtained. In the presence of the weak base AcNMe2, or in the absence of base, III was the sole product. In the experiment, the researchers used many compounds, for example, N-(4-Hydroxyphenyl)-4-methylbenzenesulfonamide (cas: 1146-43-6SDS of cas: 1146-43-6).
N-(4-Hydroxyphenyl)-4-methylbenzenesulfonamide (cas: 1146-43-6) belongs to amides. Compared to amines, amides are very weak bases and do not have clearly defined acid–base properties in water. On the other hand, amides are much stronger bases than esters, aldehydes, and ketones. The presence of the amide group –C(=O)N– is generally easily established, at least in small molecules. It can be distinguished from nitro and cyano groups in IR spectra. Amides exhibit a moderately intense νCO band near 1650 cm−1. By 1H NMR spectroscopy, CONHR signals occur at low fields. In X-ray crystallography, the C(=O)N center together with the three immediately adjacent atoms characteristically define a plane.SDS of cas: 1146-43-6
Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics