Mechanochemical carbon-carbon bond formation that proceeds via a cocrystal intermediateElectronic supplementary information (ESI) available: Experimental and computational details, in situ Raman and PXRD data, thermal measurements, NMR data and FTIR data. CCDC 1869002 and 1818969. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c8cc07853j

We report the first cocrystal as an intermediate in a solid-state organic reaction wherein molecules of barbituric acid and vanillin assume a favorable orientation for the subsequent Knoevenagel condensation. In situ Raman monitoring revealed the first cocrystal as an intermediate in a mechanochemical organic reaction.