Ammonium, tetrabutyl-, hydroxide Benzene,

N-Alkylation of 1,2,3-triazoles and benzotriazoles is readily achieved using (1) alkyl halides, dialkyl sulfates, diazoalkanes, and jS-tosylates or (2) the Mannich reaction. When alkyl halides are used, sodium alkoxide, sodium hydride, or sodium hydroxide is usually employed as the base. The N-alkylation of benzotriazole with alkyl halides proceeds efficiently using powdered NaOH as the base in DMF. The highest yields (80100%) of the alkylated benzotriazoles are obtained when a fourfold excess of NaOFl is employed. A-Alkylbenzotriazoles have been prepared from benzotriazole and alkyl halides using phase-transfer catalysts, e.g., KOFI, benzene, tetrabutyl-ammonium salts or KOH, benzene, polyethylene glycol. 

Differences in the structure of solutions derived from 2 polymorphic modifications of aspirin were demonstrated through differences in apparent pK values. Polymorph I was prepared by slow crystallization at room temperature from a saturated solution of aspirin in 95% ethanol. Polymorph II was prepared by crystallization from a saturated solution of aspirin in n-hexane at room temperature. The apparent pK s were determined in dimedrylformamide using tetrabutyl-ammonium hydroxide (in methanol-benzene solvent) as die titrant. The pZCa differences were ascribed to differences in intra- and intermolecular hydrogen bonding of the solute."... 

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