Extracurricular laboratory: Synthetic route of 960203-41-2

The synthetic route of 960203-41-2 has been constantly updated, and we look forward to future research findings.

Reference of 960203-41-2, A common heterocyclic compound, 960203-41-2, name is (2-Bromophenyl)(2,4-dimethylphenyl)sulfane, molecular formula is C14H13BrS, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.

Example 19; A solution of 10 gram l-(2-Bromo-phenylsulfanyl)-2,4-dimethyl-benzene (34 mmol) in 50 ml dry toluene was added 7 gram boc-piperazine (38 mmol), degassed with nitrogen for 5 minutes, added 312 mg Pd2dba3 (2 mol-%) and 637 mg ralphac-BINAP (3 mol-%), degassed for another 5 minutes before adding 3.9 gram Bu1ONa (41 mmol) and heated to 80 0C for 15 hours. The reaction mixture was cooled to RT and extracted twice with 20 ml 15 % brine, dried over Na2SO4, added charcoal, re fluxed for 15 minutes, filtered though celite and evaporated to 14.2 gram of brownish oil (4- [2-(2,4-Dimethyl-phenylsulfanyl)-phenyl]-BOC-piperazine) having a purity of 95 % determined by NMR. The crude oil was dissolved in 200 ml MeOH and 20 ml 6M HCl (aq.) and refluxed for 1 hour after which HPLC showed full deprotection. After cooling to RT the methanol was removed by vacuum on a rotary-evaporator, 20 ml cone. NaOH (pH was measured to 13-14) was added after which the mixture was stirred 15 minutes with 100 ml EtOAc. The organic phase was collected and extracted twice with 30 ml 15 % brine, dried over Na2SO4 and added 5.2 g fumaric acid (44 mmol) in 30 ml MeOH. During heating to reflux a homogenous solution forms from which a rapid precipitation takes place either during further heating or upon cooling. The precipitate was collected, washed with 20 ml EtOAc and 20 ml acetone, dried in vacuum giving 9.3 gram of l-[2-(2,4-Dimethyl-phenylsulfanyl)-phenyl]-piperazine fumarate (22 mmol) as a white powder in 66 % overall yield having a purity of 99.5 % by LC-MS.; Example 22; 500 ml toluene was placed in a IL three-necked round bottle with a mechanical stirrer and added 809 mg Pd2dba3 (0.88 mmol; 0.5 mol-%) and 952 mg DPEPhos (1.77 mmol; 0.5 mol-%). The dark-red solution was purged with nitrogen for 5 minutes before addition of 100 g 2-bromoiodobenzene (353 mmol) and 48.9 g 2,4- dimethylthiophenol (353 mmol) took place. Addition of 43.6 g KOBu’ (389 mmol) caused an exothermic reaction increasing the temperature from 20 0C to 42 0C simultaneously with the formation of a heterogeneous mixture and the colour changed from dark-red into orange/brownish. The suspension was heated to 100 0C under nitrogen. After only 20 minutes a HPLC showed full conversion into l-(2-Bromo- phenylsulfanyl)-2,4-dimethyl-benzene. The mixture was cooled to 40 0C, added 600 ml 15-wt% NaCl and stirred for 5 minutes. The organic phase was separated and the aqueous phase was washed with 2 x 100 ml toluene. The combined organic phases were washed with 100 ml 2M HCl (aq.), 100 ml 15-wt% NaCl, dried over Na2SO4, refiuxed for 15 minutes with activated charcoal (10 g), filtered twice and evaporated to 107.3 g orange-red oil (103 %) that was found to be 98 % pure by HPLC.A solution of 90 gram of the orange-red oil (307 mmol) in 500 ml dry toluene was added 57 gram boc-piperazine (307 mmol), degassed with nitrogen for 5 minutes, added 1.4 g Pd2dba3 (1.53 mmol; 0.5 mol-%) and 2.9 g ralphac-BINAP (4.6 mmol; 1.5 mol-%), degassed for another 2 minutes before adding 35.4 gram Bu1ONa (368 mmol) and heated to 80 0C for 18 hours. HPLC showed full conversion and the reaction mixture was cooled to RT, filtered and the filter cake was washed with 2 x 100 ml toluene. The combined filtrates was extracted twice with 2 x 150 ml 15-wt% NaCl, dried over Na2SO4, added charcoal, refiuxed for 30 minutes, filtered twice and evaporated to 140.7 gram of brownish oil (4-[2-(2,4-Dimethyl-phenylsulfanyl)- phenyl]-BOC-piperazine). The crude oil was dissolved in 300 ml MeOH and 200 ml 6M HCl (aq.) and refiuxed for 1 hour after which HPLC showed full deprotection. After cooling to RT the methanol was removed by vacuum on a rotary-evaporator, 200 ml cone. NaOH (pH was measured to 13-14) was added after which the mixture was stirred 15 minutes with 1000 ml EtOAc. The organic phase was collected and extracted with 300 ml 15-wt% brine, dried over Na2SO4 and added to a solution of 46.3 g fumaric acid (399 mmol) in 300 ml MeOH. The mixture was heated to reflux, cooled to room temperature and then left in the freezer overnight (-18 0C). The precipitate was collected, washed with 100 ml EtOAc and 100 ml acetone, dried in vacuum (50 0C) producing 103.2 g of l-[2-(2,4-Dimethyl-phenylsulfanyl)-phenyl]- piperazine fumarate (249 mmol) as a white powder in 81 % overall yield having a purity of 99 % by LC-MS. The fumarate was transfer into the free base (l-[2-(2,4- Dimethyl-phenylsulfanyl)-phenyl]-piperazine) using EtOAc/H2O/conc. NaOH, the organic phase was washed with brine, dried using Na2SO4, filtered and to the filtrate was added 34 ml 48-wt% HBr (aq.) causing a precipitation of a white solid. The solid was collected, treated with 1000 ml boiling H2O, which upon cooling to room temperature formed a slurry. The final product (l-[2-(2,4-Dimethyl-phenylsulfanyl)- phenylj-piperazine hydrobromide) was collected by filtration and dried in vacuum (50 0C) producing 83 g of white powder (71 % …

The synthetic route of 960203-41-2 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; H. LUNDBECK A/S; WO2007/144005; (2007); A1;,
Bromide – Wikipedia,
bromide – Wiktionary