Study on the new synthetic method of 1,2-pentanediol and process optimization thereof was written by Xu, Bao-ming;Tang, Qiang;Luo, Yan;Cheng, Qian;Chen, Kun. And the article was included in Gaoxiao Huaxue Gongcheng Xuebao in 2014.SDS of cas: 32446-47-2 This article mentions the following:
A new feasible synthetic route for the synthesis of 1,2-pentanediol was designed and optimized in this paper with butyraldehyde and paraformaldehyde as the starting material. The effects of feed ratio, reaction temperature, catalyst dosage and reaction pressure on the yield of product were studied. The reaction was divided into two steps. The first step, using 3-Et benzothiazole bromide as catalyst, the intermediate product 1-hydroxy-2-pentanone was synthesized by cross-acyloin condensation between n-butyraldehyde and paraformaldehyde. The optimum condition is: n (butyraldehyde): n (paraformaldehyde) = 1:1.5, n (Bu aldehyde): n (catalytic agent) = 1:0.1, temperature 70掳C, the average yield obtained by six repeated experiments is 56.6%. In the second step, the final product 1,2-pentanediol was synthesized with hydrogenation reduction of 1-hydroxy-2-pentanone by using Pd/C as catalyst. The optimum condition is: Pd/C catalyst dosage 3.5% (relative to the 1-hydroxy-2-pentanone quality), hydrogen pressure 1.5 MPa, temperature 55掳C, the average yield obtained by six repeated experiments is 91.6%. Total yield of two steps is 51.8%, the cost of material is only 40,000 yuan/ton. The structures of product were analyzed and characterized by IR, 1H-NMR, MS. This process has advantages of easy available raw material, simple technol. with mild reaction conditions, high content of the product and suitable for industrialized production In the experiment, the researchers used many compounds, for example, 3-Ethylbenzo[d]thiazol-3-ium bromide (cas: 32446-47-2SDS of cas: 32446-47-2).
3-Ethylbenzo[d]thiazol-3-ium bromide (cas: 32446-47-2) belongs to thiazole derivatives. Thiazoles are a class of five-membered rings containing nitrogen and sulfur with excellent antitumor, antiviral and antibiotic activities. Thiazole sulfonation occurs only under forcing conditions: the action of oleum at 250 掳C for 3 hours in the presence of mercury(II) sulfate leads to 65% formation of 5-thiazole sulfonic acid.SDS of cas: 32446-47-2
Referemce:
Thiazole | C3H3NS – PubChem,
Thiazole | chemical compound | Britannica