Process for preparing 1,5-benzothiazepine derivatives
AssigneeTanabe Seiyaku Co., Ltd.
InventorsTadayuki Koumoto, Hironori Hayashi, Toshiya Kadowaki, Masahiko Seto, Toyonari Oine
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Abstract
There is disclosed a process for preparing 1,5-benzothiazepine derivatives of the formula: ##STR1## wherein R.sup.1 is a lower alkyl group, or a salt thereof which comprises subjecting a propionate derivatives of the formula: ##STR2## wherein R.sup.2 is an ester residue and R.sup.1 is the same as defined above, to intramolecular cyclization in the presence of a sulfonic acid compound of the formula: R.sup.3 SO.sub.3 H (III) wherein R.sup.3 is a lower alkyl group or a substituted or unsubstituted phenyl group, in a non-halogenated organic solvent and, if desired, converting the product to a salt thereof.
Claims8
A process for preparing 1,5-benzothiazepine derivatives of the formula:
- ##STR6## wherein R.sup.1 is a lower alkyl group, or a salt thereof which comprises subjecting a propionate derivative of the formula:
- ##STR7## wherein R.sup.2 is a lower alkyl group and R.sup.1 is the same as defined above, to intramolecular cyclization in the presence of a sulfonic acid compound of the formula:
- R.sup.3 SO.sub.3 H (III)
- wherein R.sup.3 is a lower alkyl group or a substituted or unsubstituted phenyl group, in a non-halogenated aromatic solvent and, optionally converting the product to a salt thereof.
A process for preparing 3-acetoxy-5-(.beta.-dimethylaminoethyl)-2,3-dihydro-1,5-benzothiazepine derivatives of the formula:
- ##STR8## wherein R.sup.1 is a lower alkyl group, or a pharmaceutically acceptable salt thereof, which comprises the steps of:
- a) subjecting a propionate derivative of the formula:
- ##STR9## wherein R.sup.2 is a lower alkyl group and R.sup.1 is the same as defined above, to intramolecular cyclization in the presence of a sulfonic acid compound of the formula:
- R.sup.3 SO.sub.3 H (III)
- wherein R.sup.3 is a lower alkyl group or a substituted or unsubstituted phenyl group, in a non-halogenated aromatic solvent to give a 1,5-benzothiazepine derivative of the formula:
- ##STR10## wherein R.sup.1 is the same as defined above, and b) converting the compound (I) to the corresponding 3-acetoxy-5-(.beta.-dimethylaminoethyl)-1,5-benzothiazepine derivative or a pharmaceutically acceptable salt thereof.
Dependencies are inferred from the claim text.