exothermically
(adverb)
adverb
1. In an exothermic manner
- Aldrichimica Acta Volume 30 No 4 (pdf) from Sigma-AldrichThe fused cyclobutenomaleimide is much more reactive than Smith’s diene; it reacts with cyclopentadiene exothermically at room temperature to yield the extended isomer as the major cycloaddition product.