7-(3-Chloropropyl)-3,7-dihydro-1,3-dimethyl-1H-purine-2,6-dione → Fluprophylline

Participants

Reaction Conditions

Reaction Steps

10.2 g 4-(p-fluorobenzoyl)-piperidine and 16.5 g 7-(chloropropyl)-theophylline are carefully mixed in the solid state and heated to 100° C. in a round flask in an oil bath. The mixture at first results in a clear melt, subsequently begins to crystallize and then changes into a solid mass. It is allowed to cool after 10 minutes, dissolved in ethyl acetate and 2n hydrochloric acid is added, whereby a dark oil separates in the organic phase, crystallizing on standing overnight. By recrystallizaing with 100 ml carbon tetrachloride, an intially oily then crystallizing substance is obtained, 7.4 g of the product with an mp of 114° to 119° C. (yield: 43.5%)

Provenance & Evidence