A novel approach to the prediction of the physical properties of polymers is presented. A QSPR study, involving the use of a newly developed statistical package, CODESSA, is described for the T g of a set of 22 low molecular weight polymers which gave a four-parameter equation with R 2 = 0.928. The physical significance of the descriptors selected is discussed.

The N-chloromethyl group of 1 -(chloromethyl) benzotriazole undergoes nucleophilic substitution by carbon, nitrogen, phosphorus, oxygen, and sulphur nucleophiles. a-Lithiation was achieved in high yield in 1 -phenylthiomethyl-, 1 -phenylsulphinylmethyl-, and 1 -(phenylsulphonylmethyl) benzotriazoles and the lithio derivatives reacted with a variety of electrophiles. New benzotriazolium salts were prepared by quaternization of the N-3 nitrogen with methyl iodide.N-Chloromethylheterocycles are important industrial intermediates. A substructure search for ClCH,-attached to an N atom in a five-or six-membered ring [cf. (l)] revealed some 800 Chemical Abstracts entries over the period 1967-83 covering chloromethyl derivatives of 44 different heterocyclic systems.

The I3C spectra of the hydroxymethyl derivatives of pyrrole, furan, 5,5-dimethylhydantoin, imidazole, thiophene, pyrazole, and phenol have been studied and assigned. The snbstitueot parameters for the hydroxymethyl group in pyrrole, thiophene, furan, and imidazole were determined.

The complex course of the reaction of pyrrole with formaldehyde has been completely elucidated by quantitative I3C NMR spectroscopy using the inverse-gated decoupling technique. The final product is 23-bis(hydroxymethy1)pyrrole (with a free l-position), but three main intermediates containing 1-hydroxymethyl groups were identified, and the rise and subsequent fall of their populations followed. The intermediacy of additional compounds (formals) also renders the reaction more complex. The molar fractions of four hydroxymethylpyrroles present in the reaction mixtures were calculated from the I3C NMR data and plotted against time. At 45 and 65°C pyrrole reacted completely with formaldehyde in 1 h and in less than 30 min, respectively. This work illustrates the utility of the 13C NMR investigation of an industrially important reaction.KEY WORDS Reaction of pyrrole with formaldehyde Hydroxymethylpyrroles 3C NMR