Crystalline, anhydrous sigma-form of 2-(4-(2-furoyl)-(2-piperazin)-1-yl)-4-amino-6,7-dimethoxy-quinazoline hydrochloride and a process for its preparation

US4816455A · kind A · utility

Assignee

• Heumann Pharma GmbH · DE

Inventors

• Helmut Schickaneder · Eckental, DE
• Ingomar Grafe · Nürnberg, DE
• Kurt H. Ahrens · Nürnberg, DE

Key dates

• Filing date: Mar 3, 1987
• Grant date: Mar 28, 1989
• Expiry date: Mar 3, 2007

Classification

• Technology area (CPC A): Human Necessities
• CPC primary: A61K31/505
• WIPO field: Pharmaceuticals
• WIPO sector: Chemistry

Abstract

A new anhydrous crystalline form of prazosine hydrochloride characterized by the following bands in the infra-red spectrum in potassium bromide is described: PA0 3445 cm.sup.-1 (2.90 .mu.m), PA0 1010 cm.sup.-1 (9.90 .mu.m) (duplet), and PA0 768 cm.sup.-1 (13.03 .mu.m). This new form is distinguished by its surprisingly great stability in storage compared with known polymorphous forms of prazosine.