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Last Updated: December 22, 2024

Claims for Patent: 5,504,207

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Summary for Patent: 5,504,207

Title:	Process and intermediate for the preparation of terazosin hydrochloride dihydrate
Abstract:	A process for the preparation of 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-(2-tetrahydrofuroyl)piperazine hydrochloride (terazosin hydrochloride dihydrate comprises the steps of reacting 4-amino-2-chloro-6,7-dimethoxy-quinazoline with N-(2-tetrahydrofuroyl)piperazine in an anhydrous polar organic solvent in the absence of an added acid scavenger to produce anhydrous 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-(2-tetrahydrofuroyl)piperazine hydrochloride (Form IV) and thereafter converting the product of that step to 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-(2-tetrahydrofuroyl)-piperazine hydrochloride dihydrate.
Inventor(s):	Mannino; Anthony (Round Lake Beach, IL), Henry; Rodger F. (Waukegan, IL), Heitmann; Wayne R. (Lindenhurst, IL), Horrom; Bruce W. (Waukegan, IL)
Assignee:	Abbott Laboratories (Abbott Park, IL)
Application Number:	08/324,635
Patent Claims:	1. A process for the preparation of 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-(2-tetrahydrofuroyl)piperazine hydrochloride dihydrate comprising the steps of a) reacting 4-amino-2-chloro-6,7-dimethoxyquinazoline with N-(2-tetrahydrofuroyl)piperzine "in a ratio of 1 to n where n is up to 1.2"in an anhydrous polar organic solvent in the absence of an added acid scavenger to produce the Form IV crystalline modification of anhydrous 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-(2-tetrahydrofuroyl)-piperazine hydrochloride; and b) thereafter converting the product of Step a) to 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-(2-tetrahydrofuroyl)piperazine hydrochloride dihydrate. 2. The process of claim 1 wherein said anhydrous polar organic solvent is selected from C.sub.1 -C.sub.4 alcohols, C.sub.1 -C.sub.4 ether-alcohols, C.sub.4 -C.sub.8 diethers and C.sub.3 -C.sub.6 ketones. 3. The process of claim 3 wherein said anhydrous polar organic solvent is methoxyethanol. 4. The anhydrous Form IV crystalline modification of 1-(4-amino-6,7-dimethoxy-2-quinazolinyl)-4-(2-tetrahydrofuroyl)piperazine hydrochloride characterized by principal peaks in the powder X-ray diffraction pattern at values of 7.15.degree..+-.0.2.degree.; 10.44.+-.0.2.degree.; 14.56.+-.0.2.degree.; 20.48.+-.0.2.degree.;21.23.+-.0.2.degree.; 22.47.+-.0.2.degree.; 23.70.+-.0.2.degree.; 24.43.+-.0.2.degree.; and 27.11.+-.0.2.degree.; of two theta.

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