The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 21, 1995
Filed:
Nov. 24, 1993
Jozsef Reiter, Budapest, HU;
Peter Trinka, Budapest, HU;
Peter Tompe, Budapest, HU;
Eva Szabo, Budapest, HU;
Peter Slegel, Budapest, HU;
Janos Brlik, Budapest, HU;
Agnes Halbauer nee Nagy, Budapest, HU;
Ilona Sztruhar, Budapest, HU;
Magdolna Kenyeres nee Feher, Budapest, HU;
Frigyes Gorgenyi, Budapest, HU;
Margit Csorgo, Budapest, HU;
Szvetlana Zsarnoczai nee Kurnyecova, Budapest, HU;
Sarolta Benko nee Markus, Budapest, HU;
Gabor Gigler, Budapest, HU;
Dezso Danyi, Budapest, HU;
Pal Fekete, Budapest, HU;
Maria Kiraly nee Ignacz, Budapest, HU;
EGIS Gyogyszergyar, Budpest, HU;
Abstract
This invention relates to a new and improved process for the preparation of 6,7-dichloro-1,5-dihydroimidazo[2,1-b]-quinazolin-2[3H]-one of formula ##STR1## (anagrelide), a valuable blood platelet antiaggregative compound. According to the process of the invention the compound of formula (I) is prepared by subjecting a new 2-cyanoiminoquinazoline derivative of the general formula ##STR2## wherein R stands for cyano or a group of the formula COOR.sup.1, in the latter R.sup.1 representing lower alkyl optionally carrying a phenyl substituent, to thermal cyclization in an acidic medium. The invention also relates to new 2-cyanoiminoquinazo-lines of the general formula (III) used for the production of anagrelide and to the preparation of the said compounds. The invention provides an advantageous process for the preparation of anagrelide which is devoid of the drawbacks of the hitherto known processes and renders possible the production of the compound of the formula (I) on industrial scale, too.