Inke, S.a.

Montserrat Armengol Asparo

Pere Dalmases Barjoan

In particular, this invention relates to the synthesis intermediates (IV), (V), (VI) and (VIII) useful for preparing zolmitriptanzohnitriptan or a pharmaceutically acceptable salt thereof, which includes a) Ppreparation of the diazonium salt of the aniline hydrochloride (II); followed by reduction and acidification to give hydrazine (III); b) In situ Reaction of the hydrazine hydrochloride (III) with &#x3b1;-keto-&#x3b4;-valerolactone, to give the hydrazone (IV); c) Fischer indole synthesis of the hydrazone (IV), to give the pyranoindolone of formula (V); d) Ttransesterification of the pyranoindolone (V) to provide the compound (VI), in which R means a straight or branched C1-C4 alkyl; e) Conversion of the hydroxyl group of the compound (VI) into dimethylamino to give the indolecarboxylate (VII), in which R means a straight or branched C1-C4 alkyl; f) Ssaponification of the 2-carboalkoxy group of the compound (VII), to provide indolecarboxylic acid (VIII); g) Ddecarboxylation of the indolecarboxylic acid (VIII), to provide zolmitriptan and, eventually, to provide a pharmaceutically acceptable salt thereof.

Synthesis intermediates useful for preparing zolmitriptan

In particular, zolmitriptan or a pharmaceutically acceptable salt thereof, which includes a) Preparation of the diazonium salt of the aniline hydrochloride (II); followed by reduction and acidification to give hydrazine (III); b) In situ Reaction of the hydrazine hydrochloride (III) with &#x3b1;-keto-&#x3b4;-valerolactone, to give the hydrazone (IV); c) Fischer indole synthesis of the hydrazone (IV), to give the pyranoindolone of formula (V); d) Transesterification of the pyranoindolone (V) to provide the compound (VI), in which R means a straight or branched C1-C4 alkyl; e) Conversion of the hydroxyl group of the compound (VI) into dimethylamino to give the indolecarboxylate (VII), in which R means a straight or branched C1-C4 alkyl; f) Saponification of the 2-carboalkoxy group of the compound (VII), to provide indolecarboxylic acid (VIII); g) Decarboxylation of the indolecarboxylic acid (VIII), to provide zolmitriptan and, eventually, to provide a pharmaceutically acceptable salt thereof.

Process for preparing zolmitriptan compounds

In particular, rizatriptan or a pharmaceutically acceptable salt thereof, which includes a) Preparation of the diazonium salt of aniline hydrochloride (II); followed by reduction and acidification to give the hydrazine (III); b) reaction in situ of the hydrazine hydrochloride (III) with &#x3b1;-keto-&#x3b4;-valerolactone, to give the hydrazone (IV); c) Fischer indole reaction of the hydrazone (IV), to give the pyranoindolone (V), optionally followed by a hydrolysis reaction to give (VI); d) Transesterification of (V) or esterification of its hydrolysis product (VI), to give (VII), where R means straight or branched C1-C4 alkyl chain; e) Conversion of the hydroxyl group of (VII) into dimethylamino, to give the indolecarboxylate (VIII), where R has the meaning defined above; f) Saponification of the 2-carboalkoxy group of (VIII) to give indolecarboxylic acid (IX); and g) Decarboxylaton of the indolecarboxylic acid (IX) to give rizatriptan and, eventually, to obtain a pharmaceutically acceptable salt thereof. The invention also relates to synthesis intermediates to obtain rizatriptan.

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Sant Joan Despi, Spain

Montserrat Armengol Asparo