Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB22655/52A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Abbott Laboratories
Original Assignee
Abbott Laboratories
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Abbott LaboratoriesfiledCriticalAbbott Laboratories
Publication of GB752332ApublicationCriticalpatent/GB752332A/en
Pharmaceuticals Containing Other Organic And Inorganic Compounds
(AREA)
Abstract
Piperazines of the formula <FORM:0752332/IV(a)/1> where R3 and R4 are aryl or substituted aryl groups and R2 is hydrogen, are made by hydrolysis and decarboxylation of the corresponding N1-carbalkoxy compounds, e.g. by refluxing with concentrated hydrochloric acid or alcoholic potash. The products are intermediates for the compounds of the parent Specification. In the examples: (1) p-chlorobenzhydryl chloride is condensed with N-carbethoxy-piperazine to give N-(p-chlorobenzhydryl) - N1 - carbethoxy - piperazine (isolated as dihydrochloride); the latter by acid hydrolysis yields N-(p-chlorobenzhydryl)-piperazine; (2) N-benzhydryl-N1-carbethoxypiperazine is made similarly and hydrolysed in alkaline solution to give N-benzhydryl-piperazine. The aryl groups may be substituted by halogen, alkyl or alkoxy. According to the Specification as open to inspection under Sect. 91, R2 may be an alkyl group containing up to 4 carbon atoms and R4 may be an alicyclic or heterocyclic group, e.g. pyrimidyl or furyl. This subject-matter does not appear in the Specification as accepted.
GB22655/52A1948-09-301949-07-23Improvements in or relating to n, mono substituted piperazines and process of preparing the same
ExpiredGB752332A
(en)
Process of purifying aromatic 1-hydroxy-2-acid amides by conversion into aromatic oxazine diones and reconversion of the said diones to purified amides