Transaminase reactions

A process for preparing the compound of formula (I):

• wherein, R7 is optionally substituted C1-C4 alkyl, and R10 is H, Cl, Br, F, CH3, CF3, CN, SO2, —OCH3, —C(O)CH3, or NO2,
• the process comprising:
• contacting a ketone substrate of formula:
• wherein R7 and R10 are as defined above,
• with a transaminase polypeptide in the presence of an amino donor, wherein said amino donor comprises isopropylamine, under reaction conditions suitable for converting the ketone substrate to the compound of formula (I),
• wherein the transaminase polypeptide comprises an amino acid sequence that has at least 90% sequence identity to the amino acid sequence of SEQ ID NO:
• 74, wherein said transaminase polypeptide comprises a substitution at the position corresponding to residue 223 of SEQ ID NO:
• 2, and is capable of converting the ketone substrate to the compound of formula (I) at a rate that is increased as compared to SEQ ID NO:2.