Method 2

Thiobarbituric acid (**2**) (67.0 mg, 0.47 mmol) and **1** (60.0 mg, 0.47 mmol) were mixed with 0.15 mL of MeOH as a LAG and ground for 1 h in a ball-mill (agate jar—5 mL agate ball—5 mm; 25 Hz). After that, the desired cocrystals were removed from the jar and used for further investigation employing analytical techniques.

### *2.2. Preparation of Barbituric Acid*/*1-Hydroxy-4,5-Dimethyl-Imidazole 3-Oxide (BA*/*HIMO) Cocrystal*
