| abstract |
A process for the preparation of penicillanic acetamido acids which consists of a) reacting a compound of the formula: ** (see formula) ** Or a silyl ester or a salt thereof, with an acylating agent of an acid of the formula: ** (see formula) ** Where b is an amino protecting group and separating the amino protecting group to produce the aforementioned compound or a pharmaceutically acceptable salt thereof and, if desired, before or after separating b, convert by known methods the product in the form of an acid free, of silyl ester or salt, in the corresponding free acid or in a pharmaceutically acceptable salt thereof; said compound of formula (II) being in the D - (-) form essentially free of the L- (+) isomer; and optionally b) treating in an aqueous solution the 6-D - (-) - 5 α -amino- α-(p-acetoxyphenylacetamido) penicillanic acid obtained in the previous step with an esterase, at a ph comprised between approximately 5,0 and 7.5; isolating the product and, if desired, converting the product into the form of 6-D - (-) - α -amino- α-( p-hydroxyphenylacetamido) free penicillanic acid or hydrate in its corresponding pharmaceutically acceptable salt. (Machine-translation by Google Translate, not legally binding) |