Benzotriazole Ring Research Articles

13C‐NMR and 1H‐NMR Chemical Shifts in a Correlation Analysis of Benzotriazole Derivatives Active as Plant Growth Regulators

AbstractFollowing preliminary observations on auxin‐like activity of several 1‐ and 2‐substituted benzotriazole isomers, a few new derivatives have been synthesized and tested. In attempting to quantify by QSAR the structural properties of a large set of compounds and with the aim to rationalize the structure‐activity relationships taken into account in a previous study by a set of indicator variables, attention was turned to the analysis of 13C‐NMR and 1H‐NMR chemical shifts relative to the substituent carbon atom attached on the nitrogen of the benzotriazole ring. The 13C‐NMR chemical shift can be useful as an independent parameter in QSAR. Considerations of the general applicability of sigma inductive constants for predicting physicochemical properties of complex heteroaromatic systems such as those under study are discussed. Finally it is shown that there are important electronic and steric components which play a major role in promoting the auxin‐like activity of compounds under examination.

Preparation of Some 2-(Methoxyphenyl)-2H-benzotriazoles and the Corresponding Hydroxyphenyl Compounds

The reaction of several substituted o- nitronitrosobenzenes with O- and p- anisidine , and 2,4- dimethoxyaniline in acetic acid gives in good yield the corresponding enitroazobenzenes which are readily reduced with thiourea dioxide ( formamidinesulfinic acid) to the corresponding 2-(methoxypheny1)-2H-benzotriazoles, demethylation of which furnished the corresponding 2- (hydroxypheny1)-2H-benzotriazoles. Demethylation of the dimethoxy derivatives was best accomplished with boron tribromide in methylene chloride, the methoxy group located ortho to the benzotriazole ring being demethylated more readily than is the para-methoxy group. The reaction of enitroazobenzenes containing a methoxy group with hydrobromic acid in acetic acid results in cleavage of the azo bond and also partial bromination to give o- nitroaniline and some of its brominated derivatives.

The Effect of Phenylbenzotriazole Derivatives on the Photoyellowing of Wool

The effects of a range of water-soluble 2 arylbenzotriazoles on the photoyellowing rate of bleached wool have been investigated. Variation in substitution pattern in the 2 aryl ring yielded vastly different effects. Some retardation of photoyellowing is observed with derivatives containing a hydroxyl group ortho to the benzotriazole ring, whereas the rate is accelerated by derivatives devoid of such a suhstituent or with an amino group in this position.

Bacterial chemotherapy, I: Synthesis of N1-substituted sulphanilamides

With the object of ascertaining the relative antibacterial merits of sulphonamides derived, among a few others, chiefly from heterocyclic ring systems, a series of N1-substituted sulphonamides containing the triazole, benzotriazole, indazole, indole, and indotriazine rings have been synthesised. Additional compounds reported are the sulphonamide derivatives of acetophenone and guanidine.