The calculated distance (air line) between Jāsim and Khān Shaykhūn is approximately 173 miles respectively 278 kilometers.
By car or train, the actual journey to Khān Shaykhūn is certainly longer, as only the direct route (as the crow flies) between Jāsim and Khān Shaykhūn has been calculated here.
Air line (approximately)
278 kilometers
150 nautical miles