Substituted 2,6-dinitrobenzaldehydes are valuable synthetic precursors and have been prepared by several methods. We report here that one reported synthetic method actually forms the 3,5-dinitro isomer, 4-tert-butyl-3,5-dinitrobenzaldehyde, instead of the claimed 2,6-isomer, 4-tert-butyl-2,6-dinitrobenzaldehyde. Improved syntheses for the large-scale preparation of both compounds and their single-crystal X-ray structures are described.