Abstract: A process is disclosed for the preparation of imidazole derivatives, in particular, 1-aryl-2-(1-imidazolyl) alkyl ethers and thioethers, and more particular for the preparation of tioconazole. The preferred process involves alpha bromination of thiophene in cyclohexane, coupling with an imidazole to form the crude product, and forming the bisulfate salt thereof. The reaction utilizes less hazardous chemicals than currently employed for the production of 1-aryl-2-(1-imidazolyl) alkyl ethers and thioethers, and may be run at room temperature.

Abstract: A novel process is disclosed for the preparation of dihydropyridine compounds and derivatives thereof, and more particularly felodipine. The process to prepare felodipine involves a two step procedure condensing 2,3-dichlorobenzaldehyde with methyl acetoacetate in the presence of a catalyst system. The resultant benzylidine intermediate is sequentially reacted with ethyl aminocrotonate to provide felodipine. The novelty of the present invention resides in part on (1) a new catalyst system not previously disclosed for the preparation of felodipine, (2) the absence of acid(s), (3) the control of reaction conditions to yield lower amounts of unreacted aldehyde compared to known reactions, (4) a simplified purification process, and (5) formation of negligible quantities of symmetrical diester byproducts.