P-toluic Acid

1. Imakonzedwa ndi catalytic oxidation ya p-xylene ndi mpweya.Mukamagwiritsa ntchito njira yamphamvu ya mumlengalenga, xylene ndi cobalt naphthenate zimatha kuwonjezeredwa mumphika wochitirapo kanthu, ndipo mpweya umayambitsidwa potentha mpaka 90 ℃.Kutentha kwamachitidwe kumayendetsedwa pa 110-115 ℃ pafupifupi maola 24, ndipo pafupifupi 5% ya p-xylene imasinthidwa kukhala p-methylbenzoic acid.Kuziziritsa kutentha kwa chipinda, fyuluta, kutsuka keke yosefera ndi p-xylene, ndi kuumitsa kuti mupeze p-methylbenzoic acid.P-xylene imasinthidwanso.Zokolola ndi 30-40%.Mukamagwiritsa ntchito njira yothira okosijeni, kutentha kwake ndi 125 ℃, kuthamanga ndi 0.25MPa, kutsika kwa gasi ndi 250L mu 1H, ndipo nthawi yochitira ndi 6h.Kenaka, xylene yosagwiritsidwa ntchitoyo inaphwanyidwa ndi nthunzi, bukhu la okosijeni la mankhwala linapangidwa acidified ndi concentrated hydrochloric acid ku pH 2, kusonkhezeredwa ndi kuzizira, ndi kusefedwa.Keke yosefera idaviikidwa mu p-xylene, kenako amasefedwa ndikuwumitsa kuti apeze p-methylbenzoic acid.Zomwe zili mu p-methylbenzoic acid zinali zoposa 96%.Njira imodzi yosinthira p-xylene inali 40%, ndipo zokolola zinali 60-70%.

2.Anakonzedwa ndi okosijeni wa p-isopropyltoluene ndi nitric acid.20% nitric acid ndi p-isopropyltoluene adasakanizidwa, kusonkhezeredwa ndi kutenthedwa mpaka 80-90 ℃ kwa 4h, kenako kutenthedwa mpaka 90-95 ℃ kwa 6h.Kuziziritsa, kusefera, recrystallization ya keke fyuluta ndi toluene kupereka p-methylbenzoic asidi mu 50-53% zokolola.Kuphatikiza apo, p-xylene idapangidwa ndi oxidized nitric acid kwa 30 h, ndipo zokolola zake zinali 58%.