Process for the preparation of teneligliptin

A process for the preparation of teneligliptin, a compound of formula I or salt or hydrate thereof, the process comprising:

• (a)(i) reacting a compound of formula 11, with bis (2-chloroethyl) amine or N-protected derivative or salt thereof to obtain a compound of formula Int-B or an N-protected derivative or salt thereof,
• Or
• (a)(ii) reacting 5-chloro-3-methyl-1-phenyl-1H-pyrazole-4-carbaldehyde, a compound of formula 30 with piperazine or N-protected derivative thereof,
• to obtain a compound of formula Int-B or an N-protected derivative or salt thereof;
• (b) reacting the compound of formula Int-B or N-protected derivative or salt thereof with a compound of formula 13 to obtain a compound of formula 14,
• wherein R is an amino protecting group selected from the group consisting of aralkyl, acyl, lower alkoxycarbonyl, aralkyloxycarbonyl, lower alkanesulfonyl, aryl sulfonyl, tri-(loweralkyl) silyl, and triphosgene;
• and
• (c) deprotecting the compound of formula 14 to obtain teneligliptin, a compound of formula I or salt or hydrate thereof.