The present invention is related to the use of spiro derivatives of Formula (I) for the treatment and/or prevention of allergic diseases, inflammatory dermatoses and other diseases with an inflammatory component. Specifically, the present invention is related to the use of spiro derivatives for the modulation of CRTH2 activity.
Two protocols have been developed for the synthesis of 1,3-di[alkoxy(aryloxy)carbonyl]-2-oxo-2,3-dihydroindoles starting from the corresponding N,O-diacyl derivatives obtained by treatment of 2-oxindoles with chloroformic acid esters and, triethylamine. The first is rearrangement of N,O-diacylated compounds in the presence of 4-dimethylaminopyridine to give N,C(3)-diacylated products with identical acyl groups in the two positions. The second involves O-deacylation of the N,O-diacylated compounds, followed by O-acylation and rearrangement resulting N,C(3)-diacylated 2-oxindoles with different acyl groups in the two positions. (C) 2000 Elsevier Science Ltd. All rights reserved.