3-Piperazinobenzisothiazole hydrochloride, cas is 87691-88-1, it is a common heterocyclic compound, the isothiazole compound, its synthesis route is as follows.,87691-88-1
88.7 g (0.837 mols, 3.21 molar equivalents) of sodium carbonate, 600 ml of acetonitrile and 66.7 g (0.261 mols, 1.0 molar equivalent) of 3- (1-piperazinyl) -1, 2- benzisothiazole hydrochloride [hydrochloride of the compound of formula (III) ] are added into a beaker –> equipped with a magnetic stirrer. The resulting white suspension is stirred for 10 minutes. At this point 60.0 g (0.261 mols, 1.0 molar equivalent) of 5- (2- chloroethyl) -6-chloro-l, 3-dihydro-indole-2- (2H) -one [compound of formula (II) wherein X is chlorine] and 0.3 g (0.002 mols, 0.008 molar equivalents) of NaI are added. The resulting brown suspension is charged into a 1 L reactor vessel, which is purged with nitrogen and heated to 120-125 C (internal pressure increases to 400-500 kPa) for 25 hours. The reaction is cooled to room temperature, stirred for 30 minutes, filtered and the solid washed with acetonitrile. A wet mixture of zipradisone and inorganic salts is obtained.The resulting wet mixture is stirred with 675 ml of water at reflux temperature for 1 h to remove inorganic salts . The suspension is cooled at room temperature, stirred for 30 minutes and filtered. The solid is washed with water, and 140 g of wet solid (corresponding to 87 g of dry material) are obtained.The wet solid is stirred again with water at reflux temperature for 1 h to remove residual inorganic salts. The suspension is cooled to room temperature, stirred for 30 minutes and filtered. The solid is washed with water, and 170 g of wet solid (corresponding to 81 g of dry- material) are obtained. HPLC analysis reveals a purity of 97.8%.To remove starting materials present in the wet solid obtained in the previous step, it is stirred twice with 400 ml of tetrahydrofuran at reflux temperature. The solution is cooled to room temperature, stirred for 30 –> minutes and filtered. The solid is washed twice with 40 ml of tetrahydrofuran at room temperature and 60 g of wet solid, corresponding to 54.8 g of dry material, are obtained.The solid obtained is ziprasidone base having a purity of 99.4% by HPLC and the global yield from the starting compound (II) or (III) is 51% molar. Potentiometric titration with HClO4: 100.03% Optionally, Ziprasidone base could be converted to ziprasidone hydrochloride.;Example 3. Large scale preparation of ziprasidone baseInto a 100 1 Hastelloy reactor are loaded:- 8 kg (31.3 mols 1.0 molar equivalent) of 3-(l- piperazinyl) -1, 2-benzisothiazole hydrochloride[hydrochloride of compound of formula (III) ] ,- 8.64 kg (37.5 mols, 1.2 molar equivalents) of 5- (2- chloroethyl) -6-chloro-l, 3-dihydro-indole-2- (2H) -one [compound of formula (II) wherein X is chlorine] ,- 10.6 kg (100 mols, 3.20 molar equivalents) of sodium carbonate,- 0.038 kg (0.25 mols, 0.008 molar equivalents) of NaIThe reactor is closed and blanketed with vacuum/nitrogen. Then, 56.3 kg of acetonitrile are loaded and the mixture is stirred for 10 minutes. The reactor is heated to reflux (80-82 C) . Then the reactor is closed and –> continued to be heated up to 120-125 C (internal pressure increases to 300 kPa) . The reaction mixture is kept under these conditions for 25 hours. Then the content is cooled down to room temperature and the solid is centrifuged and washed with 2 x 12 kg of acetonitrile. A wet solid containing ziprasidone base and inorganic salts is obtained.The resulting solid is loaded in a 100 1 Hastelloy reactor. The reactor is blanketed and 52 kg of water are loaded. The suspension is stirred at reflux conditions(80-850C; due to the presence of acetonitrile) for 1 h to remove inorganic salts. The suspension is cooled down to room temperature, stirred for 30 minutes and the solid is centrifuged and washed with 2 x 9 kg of water. 17.97 kg of wet solid are obtained.The wet solid from the previous step is loaded in a 100 1 Hastelloy reactor. The reactor is blanketed and 57 kg of tetrahydrofuran are loaded. The suspension is stirred at reflux conditions for 1 h. The suspension is cooled down to room temperature, stirred for 30 minutes and the solid is filtered through a Nutsche Filter and washed with 2 x 16 kg of tetrahydrofuran. 10.53 kg of wet solid (corresponding to 8.57 kg of dry material) are obtained.The solid obtained is ziprasidone base having a purity by HPLC of 99.2%. The global yield from the starting compound (III) is 66.3% (molar yield) . Optionally, Ziprasidone base could be converted to ziprasidone hydrochloride.Example 4 : Preparation of ziprasidone base –> 13.26 g (0.400 mols, 3.20 molar equivalents) of sodium carbonate, 10.00 g (0.039 mols, 1.0 molar equivalent) of3- (1-piperazinyl) -1, 2-benzisothiazole hydrochloride [hydrochloride of the compound of formula (III)], 10.80 g(0.0469 mols, 1.2 molar equivalent) of 5- (2-chloroethyl) -6-chloro-l, 3-dihydro-indole-2- (2H) -one [compound of formula (II) wherein X is chlorine] and 7.030 g (0.0469 mols, 1.2 molar equivalents) of NaI are added into a 250 ml round bottom, three necked reaction vessel, equi…
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Reference£º
Patent; MEDICHEM, S.A.; WO2006/34964; (2006); A1;,
Isothiazole – Wikipedia
Isothiazole – ScienceDirect.com