A compound of the formula (I) or a pharmaceutically acceptable salt thereof:
[wherein
X
1
and X
2
each is independently lower alkylene;
X
3
is ═CH
2
, ═CHF or ═CF
2
;
R
1
is substituent,
R
2
and R
3
each is independently H or lower alkyl; n is 0, 1, 2, 3 or 4.]having the activity inhibiting DPP-IV activity. They are therefore useful in the treatment of conditions mediated by DPP-IV, such as NIDDM.
A compound of the formula (I) or a pharmaceutically acceptable salt thereof:
[wherein
X1 and X2 each is independently lower alkylene;
X3 is ═CH2, ═CHF or ═CF2;
R1 is substituent,
R2 and R3 each is independently H or lower alkyl;
n is 0, 1, 2, 3 or 4.]
having the activity inhibiting DPP-IV activity. They are therefore useful in the treatment of conditions mediated by DPP-IV, such as NIDDM.