33543-91-8Relevant academic research and scientific papers
Production process of 2-(tetrazol-5-yl)-4-oxo-4H-benzopyran
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, (2008/06/13)
There is disclosed a process for producing a 2-(tetrazol-5-yl)-4-oxo-4H-benzopyran of general formula (1): STR1 which comprises reacting a hydroxyacetophenone of general formula (2): STR2 with a tetrazole compound of general formula (3): STR3 in the presence of a base in a solvent composed mainly of at least one selected from hydrocarbons, halogenated hydrocarbons and alcohols, and then treating the reaction mixture under acidic conditions.
A direct and high yielding route to 2-(5-tetrazolyl) substituted benzopyran-4-ones: Synthesis of pranlukast
Geen, Graham R.,Giles, Robert G.,Grinter, Trevor J.,Hayler, John D.,Howie, Simon L. B.,Johnson, Graham,Mann, Inderjit S.,Novack, Vance J.,Oxley, Paul W.,Quick, John K.,Smith, Neil
, p. 1065 - 1073 (2007/10/03)
A direct and high yielding route to 2-(5-tetrazolyl)benzopyran-4-ones 1, including pranlukast 1a is described. This involves the Claisen condensation reaction between the relevant hydroxyacetophenone 2 and the ethyl ester of tetrazole-2-carboxylic acid 5 to give the 1,3-diketone 6, which is then cyclised to give the desired benzopyran-4-ones 1.
