- SIDE REACTIONS IN BROMINATION OF α-ERGOCRYPTINE
-
2,3-Dihydro-2-oxo-α-ergocryptine (III) and 2,3-dihydro-2-oxo-3-hydroxy-α-ergocryptine (IV) were found as the side reaction products in bromination of α-ergocryptine (I) with bromine in the presence of water. 2,3-Dihydro-2-oxo-3-ethoxy-α-ergocryptine (V) was formed in the presence of ethanol.
- Cvak, Ladislav,Stuchlik, Josef,Schreiberova, Magdalena,Sedmera, Petr,Flieger, Miroslav
-
p. 565 - 572
(2007/10/02)
-
- Process for the preparation of 2-bromo-8-ergolinyl compounds
-
2-bromo-8-ergolinyl compounds of the formula STR1 wherein R8 is NH2, NH--CONEt2, CONH2, STR2 and STR3 wherein R1 =C1-4 -alkyl and R2 =C1-4 -alkyl and benzyl, R9 and R10 each mean hydrogen or, together, a bond, and the substituent R8 can be in the α- or β- position, and their acid addition salts, can be prepared from corresponding 8-ergolinyl compounds and their acid addition salts by bromination with elemental bromine in the presence of hydrogen bromide in a halogenated hydrocarbon.
- -
-
-
- Process for the preparation of 2-halogenated ergoline derivatives
-
The invention relates to a novel process for the halogenation in 2-position of ergot alkaloids. The process is characterized by that as a halogenating agent a system consisting of dimethylsulfoxide, a trialkylhalosilane or triarylhalosilane and optionally a hydrogen halide is used.
- -
-
-
- HALOGENATION OF INDOLE ALKALOIDS WITH HALODIMETHYLSULFONIUM HALOGENIDS AND HALODIMETHYLSULFOXONIUM HALOGENIDS
-
A new field of application of halodimethylsulfonium halogenids and halodimethylsulfoxonium halogenids had been studied.The formers were used for the halogenation of indole alkaloids, compounds of ergoline or aspidospermidine structure, and vincamine.
- Megyeri, Gabor,Keve, Tibor
-
p. 3415 - 3430
(2007/10/02)
-
- Process for the preparation of 2-halogenated ergoline derivatives
-
The invention relates to a novel process for the halogenation in 2-position of ergot alkaloids. The process is characterized by that as a halogenating agent a system consisting of dimethylsulfoxide, a trialkylhalosilane or triaryl-halosilane and optionally a hydrogen halide is used.
- -
-
-
- Process for the preparation of 2-bromo-α-ergocryptine
-
The invention relates to a novel process for the preparation of 2-bromo-α-ergocryptine and its acid addition salt by brominating α-ergocryptine in such a way that the bromination is carried out at room temperature by using a dimethylsulphoxide-hydrogen bromide mixture containing no more 0.02% of water and, if desired, converting the thus-obtained 2-bromo-α-ergocryptine to an acid addition salt in a known manner.
- -
-
-
- Process for brominating ergot alkaloids
-
The present invention provides an improved process for the production of a compound of formula I STR1 wherein R1 is carboxyl, alkoxy(C1-5)carbonyl, amido, alkyl(C1-5)amido, di(alkyl(C1-5)amido or an amido radical of formula II STR2 wherein Ra is alkyl(C1-4), Rb is alkyl(C1-4) or benzyl, and R2 is hydrogen or alkyl(C1-4), and either R3 is hydrogen and R4 is hydrogen or alkoxy(C1-4) or R3 and R4 together are a single bond, characterized in that a compound of formula III STR3 wherein R1 to R4 are as defined above, is brominated with a bromine complex of 3-bromo-6-chloro-2-methyl-imidazo[1,2-b]pyridazine.
- -
-
-
- BROMINATION OF α-ERGOCRYPTINE AND OTHER ERGOT ALKALOIDS WITH 3-BROMO-6-CHLORO-2-METHYLIMIDAZO/1,2-b/PYRIDAZINE-BROMINE COMPLEX AS A NEW BROMINATING AGENT
-
A new and improved bromination of α-ergocryptine and some other ergot alkaloids of the type 1, 2 and 3 using 3-bromo-6-chloro-2-methylimidazo/1,2-b/pyridazine-bromine complex (5) as a new brominating agent, to give purified 2-bromo derivatives in yields up to 81percent, is described.
- Stanovnik, Branko,Tisler, Miha,Jurgec, Milan,Rucman, Rudolf
-
p. 741 - 745
(2007/10/02)
-
