Abstract: A transmitting-receiving coaxial laser ranging device and an optical module are provided. The transmitting-receiving coaxial laser ranging device and the optical module optimize the structures and positions of a lens barrel, an objective lens, an ocular lens, an optical module, a laser transmitter, a laser receiver and other parts. The laser transmitter and the laser receiver are disposed on a side of a main optical path, but the objective lens, the ocular lens and two beam splitting prisms in the optical module are disposed on the main optical path. The beam splitting prisms are used to change optical paths of the emitted beam and the received beam, and the emitted beam and the received beam are ensured to be coaxial on the main optical path, such that the target can be aimed at more accurately and distance measurement is more precise, and the user can visually observe the target.

Abstract: The present invention relates to a process for synthesizing large scale a compound of formula (I), or pharmacuetically acceptable salt thereof, which is useful as the key intermediate for the synthesis of compounds for prophylaxis and treatment of a disease associated with the deposition of ?-amyloid in the brain, in particular Alzheimer's disease, and other diseases such as cerebral amyloid angiopathy, hereditary cerebral hemorrhage with amyloidosis, Dutch-type (HCHWA-D), multi-infarct dementia, dementia pugilistica and Down syndrome.

Abstract: The present invention relates to an alternative process for synthesizing a compound of formula (I), R1 is phenyl, which is unsubstituted or substituted with one, two or three substituents independently selected from halogen and C1-6alkyl; R2 is C1-6alkyl; R3 is —CxH2—; x is 1, 2, 3, 4, 5, 6 or 7; or pharmaceutically acceptable salt or diastereomer thereof, which is useful for prophylaxis and treatment of a viral disease in a patient relating to hepatitis B infection or a disease caused by hepatitis B infection.