A substrate is subjected to carboxylation, a chemical process that results in the production of a carboxylic acid. Decarboxylation is the reaction in the other direction. When referring to the reaction of carbanionic reagents with CO2, the word "carbonation" in chemistry is occasionally interchanged with "carboxylation." Generally speaking, carbonation refers to the process of producing carbonates. A common reaction in organic chemistry is carboxylation. Organic halides are often converted into carboxylic acids by carbonation, namely using Grignard reagents and organolithium compounds. In the Kolbe-Schmitt reaction, sodium phenolate (the sodium salt of phenol) is treated with carbon dioxide at high pressure (100 atm) and high temperature (390 K) to produce sodium salicylate, a precursor to aspirin. causing the resultant salicylate salt to become acidic and give salicylic acid.