nps-2143 nps-2143 nps-2143 (sb-262,470a) is a calcilytic drug which acts as an antagonist at the calcium-sensing receptor (casr), and consequently stimulates release of parathyroid hormone. calcilytic drugs have been researched as potential treatments for osteoporosis, and as the first such compound developed, nps-2143 is still widely used in research into the casr receptor as well as design of newer calcilytic agents. nps-2143identifiers iupac name 2-chloro-6-amino)-2-hydroxypropoxy]benzonitrile cas number284035-33-2 yhydrochloride: 324523-20-8 ypubchem cid6918446iuphar/bps716chemspider5293643uniiz25pj77w7vhydrochloride: u48sz6ebb3 ycomptox dashboard (epa)dtxsid10426075 chemical and physical dataformulac24h25cln2o2molar mass408.919 g·mol−13d model (jsmol)interactive image smiles n#cc2c(cl)cccc2occ(o)cnc(c)(c)cc3ccc1ccccc1c3 inchi inchi=1s/c24h25cln2o2/c1-24(2,13-17-10-11-18-6-3-4-7-19(18)12-17)27-15-20(28)16-29-23-9-5-8-22(25)21(23)14-26/h3-12,20,27-28h,13,15-16h2,1-2h3/t20-/m1/s1key:pzujqwhtirwcid-hxuwfjfhsa-n