Process for making [1.1.1]propellane

Patent metadata

Field	Value
Publication number	US-11724971-B2
Application number	US-202017634879-A
Country	US
Kind code	B2
Filing date	Aug 12, 2020
Priority date	Aug 14, 2019
Publication date	Aug 15, 2023
Grant date	Aug 15, 2023

Abstract

Processes of making [1.1.1]propellane utilize reaction conditions that include reacting 1,1-dibromo-2,2-bis(chloromethyl)cyclopropane with an effective amount of solid magnesium.

First claim

What is claimed is:

1. A process of making [1.1.1]propellane, comprising reacting 1,1-dibromo-2,2-bis(chloromethyl)cyclopropane with an effective amount of solid magnesium under substantially anhydrous reaction conditions that are selected to produce [1.1.1]propellane.

2. The process of claim 1 , wherein the substantially anhydrous reaction conditions comprise reacting 1,1-dibromo-2,2-bis(chloromethyl)cyclopropane with the solid magnesium in the presence of an aprotic ether solvent that comprises tetrahydrofuran.

3. The process of claim 2 , wherein the aprotic ether solvent further comprises an ether selected from diethylether, diethoxymethane, dibutylether, methyl tert-butyl ether, dioxane, 2-methyltetrahydrofuran, cyclopentyl methyl ether, and mixtures thereof.

4. The process of claim 2 , wherein the aprotic ether solvent further comprises a hydrocarbon solvent for the 1,1-dibromo-2,2-bis(chloromethyl)cyclopropane and the [1.1.1]propellane.

5. The process of claim 4 , wherein the hydrocarbon solvent is selected from toluene and heptane.

6. The process of claim 4 , further comprising filtering a reaction mixture resulting from the reacting to thereby at least partially remove at least one insoluble salt.

7. The process of claim 1 , wherein the effective amount of the solid magnesium is a molar excess that is at least 2×with respect to 1,1-dibromo-2,2-bis(chloromethyl)cyclopropane.

8. The process of claim 1 , wherein the substantially anhydrous reaction conditions are further selected to produce a yield of the produced [1.1.1]propellane that is about 10% or higher.

9. The process of claim 8 , wherein the yield is about 20% or higher.

10. The process of claim 8 , wherein the yield is about 30% or higher.

11. The process of claim 8 , wherein the yield is about 40% or higher.

12. The process of claim 8 , wherein the yield is about 50% or higher.

13. The process of claim 1 , wherein the substantially anhydrous reaction conditions comprise a reaction temperature in the range of about 0° C. to about 85° C.

14. The process of claim 1 , wherein the substantially anhydrous reaction conditions comprise a reaction time in the range of about 30 minutes to about 10 hours.

15. The process of claim 1 , further comprising separating at least a portion of the produced [1.1.1]propellane from a reaction mixture containing the 1,1-dibromo-2,2-bis(chloromethyl)cyclopropane and the solid magnesium.

16. The process of claim 1 , comprising contacting at least about one kilogram of 1,1-dibromo-2,2-bis(chloromethyl)cyclopropane with the effective amount of solid magnesium.

17. The process of claim 1 , further comprising purifying the produced [1.1.1]propellane to provide a purified [1.1.1]propellane that has a purity of about 90% or higher.

18. The process of claim 17 , wherein the purity is about 95% or higher.

19. The process of claim 18 , wherein the purity is about 99% or higher.

20. The process of claim 1 , wherein the substantially anhydrous reaction conditions comprise a batch condition.

21. The process of claim 1 , wherein the substantially anhydrous reaction conditions comprise a continuous flow reaction condition conducted in a continuous flow reactor.

Assignees

• Recurium Ip Holdings Llc

Inventors

• Unni Aditya Krishnan
• Pinchman Joseph Robert
• Huang Peter Qinhua
• Bunker Kevin Duane

Classifications

• C07C1/28 Primary

  by ring closure · CPC title

• C07C13/605

  with a bridged ring system · CPC title

• C07C2521/10

  Magnesium; Oxides or hydroxides thereof · CPC title

• C07C5/31 Primary

  changing the number of rings · CPC title

• C07C2603/62

  containing three- or four-membered rings · CPC title