Gary Barnett’s Extell Development locked in $73.5 million to refinance five commercial buildings in Chelsea, the Flatiron District and the Upper West Side. Deutsche Bank provided the financing, which includes $26.5 million in new loans and consolidates $47 million of existing loans on the properties, according to records filed with the city Monday. The properties include two adjacent buildings at 140 and 142 West 24th Street in Chelsea.