We dont currently carry the NPN transistor 2SC1845. Possible substitutes are NTE Electronics, Inc part # NTE2696 or onsemi part # KSC1845FTA.
DigiKey # 2368-NTE2696-ND
NTE # NTE2696
T-NPN SI 120V IC=100MA TO-92
Datasheet- nte2696 (nteinc.com)
DigiKey # KSC1845FTATB-ND
onsemi # KSC1845FTA
KSC1845FTA
Datasheet- KSC1845 - NPN Epitaxial Silicon Transistor (onsemi.com)
Please review the datasheets to ensure the alternative will work for your application.