Synthesis method of chiral cis-bromo.ammine.bis(ethylenediamine) cobalt bromide

Abstract

The invention relates to a synthesis method of chiral cis-bromo.ammine.bis(ethylenediamine) cobalt bromide, in particular to the synthesis method of the chiral cis-bromo.ammine.bis(ethylenediamine) cobalt bromide with high enantiomeric purity. The synthesis method comprises the following steps: putting trinuclear cobalt and NH4Br in a solvent for reacting to obtain an intermediate product compound; adding lambada-cis-[CoBr(NH3)(en)2]Br2 or delta-cis-[CoBr(NH3)(en)2]Br2 variety, heating and stirring, cooling and separating out a red-purple crystalline solid, filtering, washing and recrystallizing the crystalline solid; and keeping the obtained saturated solution standing and crystallizing to obtain a compound with the same chirality as the added variety. The synthesis method has the advantages of simple operation, high yield, easy control and good safety, and the chiral compound with the high enantiomeric purity can be obtained by the method. The obtained compound has stable propertiesand can be easily stored and served as a standard sample for liquid and solid test for circular dichroism.

Description

technical field

[0001] The invention relates to a synthesis method of chiral brominated cis-bromo·ammonia·bis(ethylene di)cobalt with high enantiopurity. Background technique

[0002] Absolutely asymmetric synthesis is a phenomenon of spontaneous symmetry breaking (Zhang Hui, Wang Xianying, Chen Leiqi, Fang Xueming, Gao Jingxing, Xu Zhigu. Acta Physicochemical Sinica, 2006, 22(5): 609-616), it refers to the In an achiral environment, the process of converting an achiral raw material into a chiral product. However, the result of this spontaneous symmetry breaking is difficult to predict, because the small enantiomeric excess (ee value) randomly generated in the system may achieve nonlinear amplification through a certain mechanism (Kondepudi, D.K.; Asakura, K.Acc .Chem.Res., 2001, 34(12):946-954), finally forming a product with a single chiral configuration. In 1990, Asakura et al. (K.Asakura, K.Kobayashi, Y.Mizusawa, et al.Physica.D., 1995, 84, 72-74) accidentally discover...

Examples

Embodiment 1

[0019] Will [Co(H 2 O) 2 {(μ-OH) 2 Co(en) 2} 2 ](SO 4 ) 2 ·7H 2 O (0.72g), NH 4 Br (2g) and 2g of water were mixed and stirred magnetically for 1min to form a suspension, and 0.0036gΛ-cis-[CoBr(NH 3 )(en) 2 ]Br 2 variety, then heated in a 50°C water bath and stirred for 5 minutes, and kept in a refrigerator (4°C) for more than 20 hours after cooling to obtain more crystals. The precipitated red-purple crystalline solid was filtered and washed successively with ethanol and ether to remove ammonium bromide and other by-products until no turbid liquid was washed out. The crude product was recrystallized with a minimum amount of 5% hydrobromic acid solution, and the saturated solution was left to crystallize at room temperature to obtain the compound Λ-cis-[CoBr(NH 3 )(en) 2 ]Br 2 . Yield 61.8%, Δε=0.354.

Embodiment 2

[0021] Will [Co(H 2 O) 2 {(μ-OH) 2 Co(en) 2} 2 ](SO 4 ) 2 ·7H 2 O (0.72g), NH 4 Br (2g) and 2g of water were mixed and stirred magnetically for 1min to form a suspension, and 0.0036g of Δ-cis-[CoBr(NH 3 )(en) 2 ]Br 2 variety, then heated in a 50°C water bath and stirred for 5 minutes, and kept in a refrigerator (4°C) for more than 20 hours after cooling to obtain more crystals. The precipitated red-purple crystalline solid was filtered and washed successively with ethanol and ether to remove ammonium bromide and other by-products until no turbid liquid was washed out. The crude product was recrystallized with a minimum amount of 5% hydrobromic acid solution, and the saturated solution was left to crystallize at room temperature to obtain a compound Δ-cis-[CoBr(NH 3 )(en) 2 ]Br 2. Yield 60.4%, Δε=-0.347.

Embodiment 3

[0023] Will [Co(H 2 O) 2 {(μ-OH) 2 Co(en) 2} 2 ](SO 4 ) 2 ·7H 2 O (2.14g), NH 4 Br (6.86g) and 6.8g of water were mixed and stirred magnetically for 1min to form a suspension, and 0.0107g of Δ-cis-[CoBr(NH 3 )(en) 2 ]Br 2 variety, then heated in a 50°C water bath and stirred for 5 minutes, and kept in a refrigerator (4°C) for more than 20 hours after cooling to obtain more crystals. The precipitated red-purple crystalline solid was filtered and washed successively with ethanol and ether to remove ammonium bromide and other by-products until no turbid liquid was washed out. The crude product was recrystallized with a minimum amount of 5% hydrobromic acid solution, and the saturated solution was left to crystallize at room temperature to obtain a compound Δ-cis-[CoBr(NH 3 )(en) 2 ]Br 2 . Yield 50.6%, Δε=-0.327.

technical field

[0001] The invention relates to a synthesis method of chiral brominated cis-bromo·ammonia·bis(ethylene di)cobalt with high enantiopurity. Background technique

[0002] Absolutely asymmetric synthesis is a phenomenon of spontaneous symmetry breaking (Zhang Hui, Wang Xianying, Chen Leiqi, Fang Xueming, Gao Jingxing, Xu Zhigu. Acta Physicochemical Sinica, 2006, 22(5): 609-616), it refers to the In an achiral environment, the process of converting an achiral raw material into a chiral product. However, the result of this spontaneous symmetry breaking is difficult to predict, because the small enantiomeric excess (ee value) randomly generated in the system may achieve nonlinear amplification through a certain mechanism (Kondepudi, D.K.; Asakura, K.Acc .Chem.Res., 2001, 34(12):946-954), finally forming a product with a single chiral configuration. In 1990, Asakura et al. (K.Asakura, K.Kobayashi, Y.Mizusawa, et al.Physica.D., 1995, 84, 72-74) accidentally discover...

Examples

Embodiment 1

[0019] Will [Co(H 2 O) 2 {(μ-OH) 2 Co(en) 2} 2 ](SO 4 ) 2 ·7H 2 O (0.72g), NH 4 Br (2g) and 2g of water were mixed and stirred magnetically for 1min to form a suspension, and 0.0036gΛ-cis-[CoBr(NH 3 )(en) 2 ]Br 2 variety, then heated in a 50°C water bath and stirred for 5 minutes, and kept in a refrigerator (4°C) for more than 20 hours after cooling to obtain more crystals. The precipitated red-purple crystalline solid was filtered and washed successively with ethanol and ether to remove ammonium bromide and other by-products until no turbid liquid was washed out. The crude product was recrystallized with a minimum amount of 5% hydrobromic acid solution, and the saturated solution was left to crystallize at room temperature to obtain the compound Λ-cis-[CoBr(NH 3 )(en) 2 ]Br 2 . Yield 61.8%, Δε=0.354.

Embodiment 2

[0021] Will [Co(H 2 O) 2 {(μ-OH) 2 Co(en) 2} 2 ](SO 4 ) 2 ·7H 2 O (0.72g), NH 4 Br (2g) and 2g of water were mixed and stirred magnetically for 1min to form a suspension, and 0.0036g of Δ-cis-[CoBr(NH 3 )(en) 2 ]Br 2 variety, then heated in a 50°C water bath and stirred for 5 minutes, and kept in a refrigerator (4°C) for more than 20 hours after cooling to obtain more crystals. The precipitated red-purple crystalline solid was filtered and washed successively with ethanol and ether to remove ammonium bromide and other by-products until no turbid liquid was washed out. The crude product was recrystallized with a minimum amount of 5% hydrobromic acid solution, and the saturated solution was left to crystallize at room temperature to obtain a compound Δ-cis-[CoBr(NH 3 )(en) 2 ]Br 2. Yield 60.4%, Δε=-0.347.

Embodiment 3

[0023] Will [Co(H 2 O) 2 {(μ-OH) 2 Co(en) 2} 2 ](SO 4 ) 2 ·7H 2 O (2.14g), NH 4 Br (6.86g) and 6.8g of water were mixed and stirred magnetically for 1min to form a suspension, and 0.0107g of Δ-cis-[CoBr(NH 3 )(en) 2 ]Br 2 variety, then heated in a 50°C water bath and stirred for 5 minutes, and kept in a refrigerator (4°C) for more than 20 hours after cooling to obtain more crystals. The precipitated red-purple crystalline solid was filtered and washed successively with ethanol and ether to remove ammonium bromide and other by-products until no turbid liquid was washed out. The crude product was recrystallized with a minimum amount of 5% hydrobromic acid solution, and the saturated solution was left to crystallize at room temperature to obtain a compound Δ-cis-[CoBr(NH 3 )(en) 2 ]Br 2 . Yield 50.6%, Δε=-0.327.

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