The synthetic method of triflate

Abstract

The invention provides a method for synthesizing trifluoromethanesulfonate. Trifluoromethanesulfonic anhydride and orthoester are used as reaction reagents to synthesize trifluoromethanesulfonate in high yield under the mild condition. The conventional trifluoromethanesulfonate synthesizing method related by the invention not only is high in reaction temperature and inconvenient to operate, but also is difficult to separate and purify. The method provided by the invention can be used for enabling reaction under the very mild condition, and can be used for synthesizing certain unstable trifluoromethanesulfonate which is difficult to synthesize by the conventional method. Moreover, the only by-product in the product is low-boiling ester, and is very easy to remove.

Description

technical field

[0001] The invention relates to a method for synthesizing trifluoromethylsulfonate, which can efficiently synthesize various trifluoromethylsulfonate under mild conditions. Background technique

[0002] Triflate is a very useful class of reagents in organic synthesis, often used as alkylating reagents. Due to the strong electron-withdrawing ability of trifluoromethanesulfonyl, the reactivity is much higher than that of conventional alkylating reagents, such as chlorides or alkylsulfonates. Because this kind of compound is very active, only methyl triflate is relatively stable, and other triflate is prone to side reactions such as elimination and rearrangement, and needs to be synthesized and post-treated under mild conditions. At the same time, these compounds have low boiling points and are highly corrosive, so post-processing is more dangerous. Therefore, the preparation of triflate has always been a difficult problem.

[0003] The most common synthetic ...

Examples

Embodiment 1 3

[0042] Synthetic one of embodiment 1 methyl trifluoromethanesulfonate (TfOMe)

[0043] Tf 2 O+HC(OMe) 3 →TfoMe+HCO 2 Me

[0044] Under ice bath, trimethyl orthoformate (3.18g, 30mmol) was slowly added to trifluoromethanesulfonic anhydride (8.47g, 30mmol), transferred to 25°C for reaction, nuclear magnetic monitoring for 15 minutes, after the reaction was complete, depressurized Distillation gave 9.74 g of methyl trifluoromethanesulfonate as a colorless liquid, with a yield of 99%.

[0045] TfOMe: b.p.47℃ / 42mmHg; 1 H NMR (400MHz, CDCl 3 )δ4.21(s,3H); 13 C NMR (101MHz, CDCl 3 )δ118.7(q, J=321.2Hz), 61.6; 19 F NMR (376MHz, CDCl 3 )δ-74.5(s,3F).

Embodiment 2 3

[0046] Synthesis of embodiment 2 methyl trifluoromethanesulfonate (TfOMe)

[0047] Tf 2 O+MeC(OMe) 3 →TfoMe+MeCO 2 Me

[0048] Under ice bath, trimethyl orthoacetate (3.60g, 30mmol) was slowly added to trifluoromethanesulfonic anhydride (8.47g, 30mmol), transferred to 25°C for reaction, nuclear magnetic monitoring for 15 minutes, after the reaction was complete, depressurized Distillation gave 9.65 g of methyl trifluoromethanesulfonate as a colorless liquid, with a yield of 98%.

Embodiment 3 3

[0049] The synthesis of embodiment 3 ethyl trifluoromethanesulfonate (TfOEt)

[0050] Tf 2 O+HC(OEt) 3 →TfOEt+HCO 2 Et

[0051]Under ice bath, triethyl orthoformate (4.44g, 30mmol) was slowly added to trifluoromethanesulfonic anhydride (8.47g, 30mmol), transferred to 25°C for reaction, 15 minutes of NMR monitoring, the reaction was completed, and the pressure was reduced Distillation gave 10.15 g of ethyl triflate as a colorless liquid, with a yield of 94%.

[0052] TfOEt: b.p.42°C (42mmHg); 1 H NMR (400MHz, CDCl 3 )δ4.62(q, J=7.1Hz, 2H), 1.51(t, J=7.1Hz, 3H); 13 C NMR (101MHz, CDCl 3 )δ118.6 (q, J=320.8Hz), 74.0, 15.2; 19 F NMR (376MHz, CDCl 3 )δ-75.2(s,3F).

technical field

[0001] The invention relates to a method for synthesizing trifluoromethylsulfonate, which can efficiently synthesize various trifluoromethylsulfonate under mild conditions. Background technique

[0002] Triflate is a very useful class of reagents in organic synthesis, often used as alkylating reagents. Due to the strong electron-withdrawing ability of trifluoromethanesulfonyl, the reactivity is much higher than that of conventional alkylating reagents, such as chlorides or alkylsulfonates. Because this kind of compound is very active, only methyl triflate is relatively stable, and other triflate is prone to side reactions such as elimination and rearrangement, and needs to be synthesized and post-treated under mild conditions. At the same time, these compounds have low boiling points and are highly corrosive, so post-processing is more dangerous. Therefore, the preparation of triflate has always been a difficult problem.

[0003] The most common synthetic ...

Examples

Embodiment 1 3

[0042] Synthetic one of embodiment 1 methyl trifluoromethanesulfonate (TfOMe)

[0043] Tf 2 O+HC(OMe) 3 →TfoMe+HCO 2 Me

[0044] Under ice bath, trimethyl orthoformate (3.18g, 30mmol) was slowly added to trifluoromethanesulfonic anhydride (8.47g, 30mmol), transferred to 25°C for reaction, nuclear magnetic monitoring for 15 minutes, after the reaction was complete, depressurized Distillation gave 9.74 g of methyl trifluoromethanesulfonate as a colorless liquid, with a yield of 99%.

[0045] TfOMe: b.p.47℃ / 42mmHg; 1 H NMR (400MHz, CDCl 3 )δ4.21(s,3H); 13 C NMR (101MHz, CDCl 3 )δ118.7(q, J=321.2Hz), 61.6; 19 F NMR (376MHz, CDCl 3 )δ-74.5(s,3F).

Embodiment 2 3

[0046] Synthesis of embodiment 2 methyl trifluoromethanesulfonate (TfOMe)

[0047] Tf 2 O+MeC(OMe) 3 →TfoMe+MeCO 2 Me

[0048] Under ice bath, trimethyl orthoacetate (3.60g, 30mmol) was slowly added to trifluoromethanesulfonic anhydride (8.47g, 30mmol), transferred to 25°C for reaction, nuclear magnetic monitoring for 15 minutes, after the reaction was complete, depressurized Distillation gave 9.65 g of methyl trifluoromethanesulfonate as a colorless liquid, with a yield of 98%.

Embodiment 3 3

[0049] The synthesis of embodiment 3 ethyl trifluoromethanesulfonate (TfOEt)

[0050] Tf 2 O+HC(OEt) 3 →TfOEt+HCO 2 Et

[0051]Under ice bath, triethyl orthoformate (4.44g, 30mmol) was slowly added to trifluoromethanesulfonic anhydride (8.47g, 30mmol), transferred to 25°C for reaction, 15 minutes of NMR monitoring, the reaction was completed, and the pressure was reduced Distillation gave 10.15 g of ethyl triflate as a colorless liquid, with a yield of 94%.

[0052] TfOEt: b.p.42°C (42mmHg); 1 H NMR (400MHz, CDCl 3 )δ4.62(q, J=7.1Hz, 2H), 1.51(t, J=7.1Hz, 3H); 13 C NMR (101MHz, CDCl 3 )δ118.6 (q, J=320.8Hz), 74.0, 15.2; 19 F NMR (376MHz, CDCl 3 )δ-75.2(s,3F).

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