The present invention is directed to a compound of Formula (I):
or a form thereof, wherein X
1
, X
2
, X
3
, X
4
, R
1
, R
2
and R
3
are as defined herein, useful as tryptase inhibitors.
本发明涉及一种化合物,其
化学式为(I)或其形式,其中X1、X2、X3、X4、R1、R2和R3的定义如本文所述,用作胰蛋白酶抑制剂。