(S)-2,3-Dihydrobenzo[1,4]dioxine-2-carboxylic Acid is an intermediate used to prepare 2-[4-(1,4-Benzodioxan-2-ylcarbonyl)piperazin-1-yl] derivatives as α1-adrenoceptor antagonists and antihypertensive agents. It is also used to synthesize G protein-coupled receptor antagonists.