US 12,227,518 B2
Crystalline polymorphs of sodium (4R,12AS)-9-{[(2,4-difluorophenyl) methyl]carbamoyl}-4-methyl-6,8-dioxo-3,4,6,8,12,12A-hexahydro-2H-pyrido [1′,2′:4,5]pyrazino[2,1-b][1,3]oxazin-7-olate and process for preparation thereof
Thirumalai Rajan Srinivasan, Hyderabad (IN); Eswaraiah Sajja, Hyderabad (IN); Rajeshwar Reddy Sagyam, Hyderabad (IN); Srinivasulu Ragineni, Hyderabad (IN); and Venkata Narasayya Saladi, Hyderabad (IN)
Assigned to MSN LABORATORIES PRIVATE LIMITED, R&D CENTER, Telangana (IN)
Appl. No. 17/428,745
Filed by MSN LABORATORIES PRIVATE LIMITED, R&D CENTER, Telangan (IN)
PCT Filed Feb. 4, 2020, PCT No. PCT/IN2020/050116
§ 371(c)(1), (2) Date Aug. 5, 2021,
PCT Pub. No. WO2020/161742, PCT Pub. Date Aug. 13, 2020.
Claims priority of application No. 201941004608 (IN), filed on Feb. 5, 2019; and application No. 201941018234 (IN), filed on May 7, 2019.
Prior Publication US 2022/0112212 A1, Apr. 14, 2022
Int. Cl. C07D 498/14 (2006.01)
CPC C07D 498/14 (2013.01) [C07B 2200/13 (2013.01)] 16 Claims
 
1. Crystalline polymorph of sodium (4R,12aS)-9-{[(2,4-difluorophenyl)methyl]carbamoyl}-4-methyl-6,8-dioxo-3,4,6,8,12,12a-hexahydro-2H-pyrido[1′,2′:4,5]pyrazino[2,1-b][1,3]oxazin-7-olate compound of formula-1a characterized by its PXRD pattern having peaks at 6.4, 11.6, 14.2 and 16.5±0.2° of 2θ.