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Biomedical subjects

AR Katritzky

Publications and source records attributed to AR Katritzky.

15 recordsLinked to original sources
PubMed2000

BtCH(2)TMS-assisted homologation of carboxylic acids: A safe alternative to the arndt-eistert reaction

One-carbon homologation of carboxylic acids is achieved by (i) treatment of an acyl chloride with 1-[(trimethylsilyl)methyl]-1H-1,2, 3-benzotriazole (BtCH(2)TMS) (1) to afford N-(acylmethyl)benzotriazoles 3a-f, followed by (ii) conversion of 3a-f with triflic anhydride into RC(OTf)=CHBt 4a-f, and (iii) the subsequent reaction of 4a-c with NaOCH(3) followed by 1N HCl to afford esters RCH(2)CO(2)R' 7a-c in overall yields of 50-70%. For the aliphatic compounds 5d-f, treatment of 5d-f with p-toluenesulfonic acid followed by TBAF/THF afforded acids RCH(2)COOH 7d-f.

Journal Article↗
PubMed2000

Polycyclic heteroaromatics from reactions of acylbenzotriazoles with aryl isocyanates

N-Acylbenzotriazoles react with aryl isocyanates to form, depending on the type of acyl group, compounds based on five different classes of polycyclic heteroaromatics. Higher alkanoyl-, acetyl-, acetoacetyl-, aroyl-, and cinnamoylbenzotriazoles yield, respectively, derivatives of quinoline, pyrimidino[5,4-c]quinoline, benzo[b]-1,8-naphthyridine, phenanthridine, and indolo[2, 3-b]quinoline by incorporating 3, 3, 4, 2, and 2 molecules, respectively, of the isocyanate per acylbenzotriazole molecule.

Journal Article↗
PubMed1997

Predicting Surfactant Cloud Point from Molecular Structure

A general empirical relationship has been developed for estimating the cloud point of pure nonionic surfactants of the alkyl ethoxylate class. For a set of 62 structures, composed of linear alkyl, branched alkyl, cyclic alkyl, and alkylphenyl ethoxylates, cloud points can be estimated to an accuracy of ±6.3°C (3.7°C median error) using the logarithm of the number of ethylene oxide residues and three topological descriptors that account for hydrophobic domain variation. Copyright 1997Academic Press

Journal Article↗
PubMed1997

Prediction of Critical Micelle Concentration Using a Quantitative Structure-Property Relationship Approach

Relationships between the molecular structure and the critical micelle concentration (cmc) of anionic surfactants were investigated using a quantitative structure-property relationship approach. Measured cmc values for 119 anionic structures, representing sodium alkyl sulfates and sodium sulfonates with a wide variety of hydrophobic and hydrophilic structures, were considered. The best multiple linear regression model involved three terms (descriptors) and had a correlation coefficient of R2 = 0.940. Very good correlations (R2 = 0.988) were obtained using three descriptors for a subset of 68 structures, with structural variation only in the hydrophobic domain. From the descriptors used in these regressions, one can conclude that the cmc is primarily dependent on the size (volume or surface area) of the hydrophobic domain and to a lesser extent on the structural complexity of the surfactant molecule.

Journal Article↗