Process for preparing pharmaceutical compound and intermediates thereof

The process of producing a compound of formula VIII

• or a pharmaceutically acceptable salt thereof comprising the steps of
• a) reacting a compound of formula VII or an acid addition salt thereof
• wherein R1 is —(CO)NH2, —CH2NH2 or —CN;
• R2═R3═H or R2 and R3 together form a cyclic boronate or borate ester;
• X is a helping group selected from the group consisting of i) a five or six membered heterocyclic aromatic ring and derivatives thereof comprising at least one N-atom being a part of an imine-group, wherein said N-atom forms the point of connection to the cyclohexapeptide ring, and ii) tetrazolyl and derivatives thereof for which a nitrogen atom forms the point of connection to the cyclohexapeptide ring, with 1,2-diaminoethane to obtain a compound of formula VIII or a pharmaceutically acceptable salt thereof and
• b) optionally isolating the compound of formula VIII or a pharmaceutically acceptable salt thereof as obtained in step a).

The process of producing caspofungin (I)

• or a pharmaceutically acceptable salt thereof comprising the steps of
• a) reacting the compound of formula IX or an acid addition salt thereof
• wherein R1 is —(CO)NH2, —CH2NH2 or —CN with i) a five or six membered heterocyclic aromatic compound and derivatives thereof comprising at least one N-atom being a part of an imine-group, or ii) tetrazole and derivatives thereof to form a compound of formula VII
• wherein R1 and X are as defined above;
• R2═R3═R or R2 and R3 together form a cyclic boronate or borate ester;
• b) followed by substituting X with 1,2-diaminoethane to give a compound of formula VIII or a pharmaceutically acceptable salt thereof
• c) optionally isolating the compound of formula I or a pharmaceutically acceptable salt thereof, provided that if R1 in formula IX is —(CO)NH2 or —CN a reduction is performed before or after step a) or b), respectively to afford the compound of formula I as the final product.