Research On Synthesis Of Paricalcitol And Halofuginone Coccidiostais

This paper is made up of the synthesis of Paricalcitol and Halofuginone coccidiostats.Part I is focusing on the synthesis of Paricalcitol. Paricalcitol (Chemical Name: la,25-dihydroxyvitamin D2), is an excellent drug of treating secondary hyperparathyroidism (SHPT) for chronic kidney disease (CDK) patients. It was firstly developed by American company Abbott. Deluca has done the creative job of synthesis of Parlicalcitol in1990s and a lot of synthetic routes have been published since then. In this paper, a novel and applicable synthetic route of Paricalcitol was described:Vitamin D2was employed as raw material through add protective group, cyclization,10,19-double bond oxidation, sulfonylation, reduction, borohydride oxidation and replacement of protective group to give19-nor-la-hydroxyvitaminD2, then25-hydroxylation was achieved by biotransformation. The total yield is about3%.The second part is focusing on the synthesis of Halofuginone coccidiostats. Halofuginone (Chemical Name:7-Bromo-6-chloro-3-(3-(3-hydroxy-2-PiPeridyl)-2-oxoProPyl)-4(3H)-quinazolinone), which is an execellent coccidiostats for poultry, has been widely used all over the world. However, owing to the complicated synthesis and industrialization of the intermediate of Halofuginone piperidine ring, we can only use Halofuginone by import with high price in China,so it is impitant for us to realize its industrialization. A lot of optimization and innovation have been done in the synthetic route of Halofuginone in this paper,2-methyl-3-hydropyridine was employed as the raw material through methylation, catalytic hydrogenation of pyridine ring, bromination to give the piperidine ring; then link the piperidine ring and7-bromo-6-chloro-4(3H)-quinazolinone to give the Halofuginone, the total yield is approximately10.0%.