| abstract |
The current invention is directed towards a polymorph of N-{2-[(2E)-2-(mesitylimino)-9, 10-dimethoxy-4-oxo-6, 7-dihydro-2H-pyrimido[6, 1-a]-isoquinolin-3(4H)-yl]ethyl}urea, in the form of a crystalline solid consisting of greater than 99% by weight of N-{2-[(2E)-2-(mesitylimino)-9, 10-dimethoxy-4-oxo-6, 7-dihydro-2H-pyrimido[6, 1-a]-isoquinol in-3(4H)-yl]ethyl}urea, at least 95% in the polymorphic form of a thermodynamically stable polymorph (I) of N-{2-[(2E)-2-(mesitylimino)-9, 10-dimethoxy-4-oxo-6, 7-dihydro-2H-pyrimido[6, 1-a]-isoquinolin-3(4H)-yl]ethyl}urea, wherein said polymorph is determined by single crystal X-ray structural analysis and X-ray powder diffraction pattern. |