Aurora kinase inhibitors and uses thereof

A compound of formula (1), an optical isomer, a crystalline form, or a pharmaceutically acceptable salt thereof:

• in formula (1):
• R1 is aryl, heteroaryl,
• wherein the aryl and the heteroaryl is optionally substituted by 1-3 groups selecting from the group consisting of halogen, C1-C3 alkyl, C1-C3 alkoxyl, halogen substituted C1-C3 alkyl or halogen substituted C1-C3 alkoxyl;
• R2 is H or methyl;
• R3 is H or F;
• W is
• wherein Ra is H, C1-C3 alkyl or C3-C6 cycloalkyl, Rb is H, C1-C3 alkyl or C3-C6 cycloalkyl;
• and
• L is CH2, CO, CD2, CH(Me), C(Me)2,
• when W is
• and Rb is H, C2-C3 alkyl or C3-C6 cycloalkyl;
• or L is CO, CD2, CHMe, C(Me)2,
• when W is
• and Rb is methyl.