  We present a preliminary measurement of the time-dependent CP-violating
asymmetry in decays of neutral B mesons to the final states D*-+ pi+- using
approximately 178 million BB events recorded by the BaBar experiment at the
PEP-II e+e- storage ring. Events containing these decays are selected with a
partial reconstruction technique, in which only the high-momentum pi+- from the
B decay and the low-momentum pi-+ from the D*-+ decay are used. % We measure
the amplitude of the asymmetry to be $-0.041 \pm 0.016 (stat.) \pm 0.010
(syst.)$ and determine bounds on $|\sin(2 \beta + \gamma)|$.
