SYNTHESIS OF N-VINYL COMPOUNDS BY REACTING NH-COMPOUNDS WITH ACETYLENE IN PRESENCE OF HOMOGENEOUS PHOSPHINE CATALYST

Abstract

A process to produce N-vinyl compounds by homogeneous catalysis can be performed. Acetylene is reacted with a compound having at least one nitrogen bearing a substitutable hydrogen residue in a liquid phase in the presence of at least one phosphine as a catalyst to produce the compounds.

Claims

1-7. (canceled)

8: A process for producing an N-vinyl compound by homogeneous catalysis, the process comprising: reacting acetylene with a compound having at least one nitrogen bearing a substitutable hydrogen residue in a liquid phase in the presence of one phosphine as a catalyst, either a solvent selected from the group consisting of linear ethers, cyclic ethers, linear amides, cyclic amides, sulfoxides, nitriles, and halogenated hydrocarbons, or without a solvent, and no metal atom or ion binding the phosphine as a ligand.

9: The process according to claim 8, wherein, in the compound having at least one nitrogen bearing the substitutable hydrogen residue, a pKa determined in dimethylsulfoxide of the substitutable hydrogen is in a range of 14 to 28.

10: The process according to claim 8, wherein the one phosphine used as the catalyst is a trialkylphosphine.

11: The process according to claim 10 wherein the trialkylphosphine is tri-n-butylphosphine or tri-n-octylphosphine.

12: The process according to claim 10, wherein other than the trialkylphosphine, no further catalyst is used.

13: The process according to claim 8, wherein the process is performed in the presence of a solvent selected from the group consisting of dimethyl formamide, dimethylacetamide, and diglyme, or without a solvent.

14: The process according to claim 8, wherein the produced N-vinyl-compound is at least one selected from the group consisting of 3-vinyl-5-methyl-1,3-oxazolidin-2-one and N-vinylpyrrolidinone.

Description

EXAMPLES

Experiments in ACE-Tubes:

[0106] Inside a Glove Box (Ar), an ACE-Tube (4 mL volume, thick-walled glass tube with Teflon screwcap, sealed with a teflon O-ring) was charged with substrate (usually: Pyrrolidinone, 85.1 mg, 1.00 mmol, 1.00 equiv.) and phosphine catalyst (usually: Tributylphosphine, 20.2 mg, 0.100 mmol, 10.0 mol %). A Teflon coated magnetic stirring bar was added and the tube was filled with a freshly prepared solution of acetylene in dimethyl acetamide (DMAA) (3.50 mL, ca. 0.70 M/ca. 1.90 wt, ca. 2.45 mmol, ca. 2.45 equiv.), prepared by bubbling solvent-free and dried acetylene through absolute DMAA, or with a freshly prepared solution of acetylene in dimethyl formamide (DMF) (3.50 mL, ca. 0.60 M/ca. 1.65 wt, ca. 2.10 mmol, ca. 2.10 equiv.), prepared by bubbling solvent-free and dried acetylene through absolute DMF (concentration of substrate: 0.286 M). The tube was then sealed and heated by a metal heating block for 16 h at 120, 130 or 140? C. The tube was then cooled to room temperature and mesitylene (30.0 ?L) was added as an internal GC standard. The reaction mixture was then filtered through a syringe filter and analyzed by calibrated GC or by GC in combination with .sup.1H-NMR.

[0107] Analysis was done on an Agilent Technologies 6890N gas chromatograph with a split/splitless injector and an FID detector. The column used was an Agilent Technologies DB-1 capillary column (30 m*0.25 mm, 1 ?m) with Helium as carrier gas.

[0108] GC method: Split: 50/1, 2.0 mL/min, const. pressure, 80? C.-1 min-15? C./min-250? C.-5 min. NMR analysis was done on a Magritek Spinsolve 60 Phosphorus Ultra NMR spectrometer with an .sup.1H frequency of 60 MHz. The samples were measured in non-deuterated DMAA as a solvent. Proton spectra were achieved with 4 scans, 6.4 sek acquisition time per scan, 30 sek repetition time and a pulse angle of 90?. Conversion to the viny compound was detected by the three characteristic proton resonances of the vinyl group.

Characteristic Example (Given in ppm)

[0109] .sup.1H-NMR (60 MHZ, DMAA) ?=6.85 (dd, .sup.3J.sub.HH=16.2 Hz, .sup.3J.sub.HH=9.5 Hz, 1H, NCH), 4.10 (d, .sup.3J.sub.HH=16.6 Hz, 1H, NCHCH.sub.2), 3.85 (d, .sup.3J.sub.HH=9.5 Hz, 1H, NCHCH.sub.2).

Experiments in NMR-Tubes:

[0110] Inside a Glove Box (Ar), a J. Young NMR tube was charged with a solution of substrate (0.150 mmol, 1.00 equiv.) and tributylphosphine (6.1 mg, 30 ?mol, 20 mol %) in absolute dimethyl acetamide (DMAA) (600 ?L, 0.250 M). The tube was sealed with a septum cap and solvent-free and dried acetylene was bubbled through via steel cannula. The septum cap was then replaced inside the Glove Box with a J. Young cap. Then, the NMR tube was heated to 110? C. by a metal heating block for 1 h and subsequently analyzed by NMR spectroscopy (.sup.1H and .sup.31P). This process was repeated for 120? C., 130? C., 140? C. and once more for 140? C. NMR analysis was done on a Magritek Spinsolve 60 Phosphorus Ultra NMR spectrometer with an .sup.1H frequency of 60 MHz. The samples were measured in non-deuterated DMAA as a solvent. Proton spectra were achieved with 4 scans, 6.4 sek acquisition time per scan, 30 sek repetition time and a pulse angle of 90?. Conversion to the viny compound was detected by the three characteristic proton resonances of the vinyl group.

Characteristic Example (Given in ppm)

[0111] .sup.1H-NMR (60 MHZ, DMAA) ?=6.85 (dd, .sup.3J.sub.HH=16.2 Hz, .sup.3J.sub.HH=9.5 Hz, 1H, NCH), 4.10 (d, .sup.3J.sub.HH=16.6 Hz, 1H, NCHCH.sub.2), 3.85 (d, .sup.3J.sub.HH=9.5 Hz, 1H, NCHCH.sub.2).

##STR00004##

ACE-Tube, Analysis by Calibrated GC

[0112]

TABLE-US-00001 # Phosphine conv./yield (sel.) A P(nBu)3 87%/68% (78%) B P(tBu)3 53%/29% (54%) C P(Cy)3 33%/14% (42%) D P(nOct)3 88%/67% (78%) E P(2-furyl)3 trace F P(Me)3 72%/46% (64%) G PPh3 2%/1% (82%)

##STR00005##

ACE-Tube, Analysis by Calibrated GC

[0113]

TABLE-US-00002 # Phosphine conv./yield (sel.) A P(nBu)3 96%/77% (80%) B P(tBu)2Me 97%/75% (77%) C dcpb 100%/65% (65%) D dcpe 83%/59% (71%) E dcpm 91%/78% (86%)

##STR00006##

TABLE-US-00003 Substrate: pK.sub.a.sup.DMSO Yield Conditions [00007] 24.2.sup.a isolated yield: 61% 5 mol %, neat, 140? C., 1.5 bar C.sub.2H.sub.2 [00008] 24.2.sup.a isolated yield: 84% 1.5 mol % P(Oct).sub.3, neat, 140? C., 6 hours, 6 bar C.sub.2H.sub.2 [00009] 27.2.sup.b isolated yield: 64% 5 mol %, neat, 140? C., 1.5 bar C.sub.2H.sub.2 [00010] 19.4.sup.e 1H-NMR Int: 0/100 20 mol %, C.sub.2H.sub.2 solution in DMAA, 140? C., 1 h [00011] 18.6.sup.c isolated yield: 46% 5 mol %, DMAA, 140? C., 1.5 bar C.sub.2H.sub.2 [00012] 23.sup.d 1H-NMR Int: 15/85 20 mol %, C.sub.2H.sub.2 solution in DMAA, 140? C., 3 h [00013] 20.8.sup.d 1H-NMR Int: 85/15 (GC Signals overlap) 10 mol %, C.sub.2H.sub.2 solution in DMAA, 120? C., 16 h + 18.4.sup.e isolated yield: 5 mol %, DMAA, 140? C., 52% 1.5 bar C.sub.2H.sub.2 [00014] 18.4.sup.e isolated yield: 53% 4 mol % P(Oct).sub.3, neat, 140? C., 17 bar C.sub.2H.sub.2 [00015] 24.4.sup.e GC-Int: 37 monovi- nyl/56 (Divinyl) 5 mol %, DMAA, 140? C., 1.5 bar C.sub.2H.sub.2 [00016] 19.9.sup.d isolated yield: 95% 5 mol %, DMAA, 140? C., 1.5 bar C.sub.2H.sub.2 [00017] 21.0.sup.d isolated yield: 83% 5 mol %, DMAA, 140? C., 1.5 bar C.sub.2H.sub.2 [00018] 16.4.sup.c isolated yield: 24% 5 mol %, DMAA, 140? C., 1.5 bar C.sub.2H.sub.2 [00019] 14.8.sup.c 1H-NMR Int: 40/60 20 mol %, C.sub.2H.sub.2 solution in DMAA, 160? C., 3 h [00020] 19.8.sup.c 1H-NMR int: 0/100 20 mol %, C.sub.2H.sub.2 solution in DMAA, 160? C., 2 h pK.sub.a-values were adapted from the literature (measured by the spectrophotometric method in DMSO against indicator at 25? C., see: J. Am. Chem. Soc. 1975, 97, 7006-7014 and J. Org. Chem. 1980, 46, 3295-3299.) .sup.aF. G. Bordwell, H. E. Fried, J. Org. Chem. 1991, 56, 4218-4223. .sup.bB. Valtera, M. I. Terekhova, E. S. Petrov, J. Stehlicek, J. Sebenda, Collect. Czech. Chem. Commun. 1985, 50, 834-839 .sup.cF. G. Bordwell, Acc. Chem. Res. 1988, 21, 456-463. .sup.dF. G. Bordwell, G. E. Drucker, H. E. Fried, J. Org. Chem. 1981, 46, 632-635. .sup.epK.sub.a values calculated by DFT

[0114] Not-isolated yields are usually calculated by addition of GC-resp. NMR-integrals of starting material and product and normalizing the corresponding integrals by this value. Overlapping GC-signals are integrated as automatically done by the ChemStation software, which usually leads to a slight bias towards product formation (underlying broader signal of starting material).

Experiments in Premex (Tall) Stainless Steel Autoclave:

[0115] Inside a Glove Box (Ar), a crimp vial (glass, 10 mL volume) was charged with substrate (usually: Pyrrolidinone, 170.2 mg, 2.00 mmol, 1.00 equiv.) and phosphine catalyst (usually: Tributylphosphine, 20.2 mg, 0.100 mmol) was added. If necessary, dimethyl acetamide (DMAA) was added (0.185 mL or 0.930 mL, 2.00 mmol or 10.0 mmol, 1.00 equiv. or 5.00 equiv.). %). A Teflon coated magnetic stirring bar was added and the vial was sealed with a septum cap, the septum was punctuated with a stainless steel cannula and placed inside a Premex (tall) stainless steel autoclave (60 mL volume) with a Kalrez O-ring. The autoclave was then sealed under argon, purged three times with solvent-free and dried acetylene and finally charged with acetylene (1.5 bar). The autoclave was then heated by a metal heating block for 16 h at 110-150? C. The autoclave was then cooled to room temperature and depressurized via a bubble counter. After opening the autoclave, mesitylene (30.0 ?L) was added to the crimp vial as an internal GC standard and the reaction mixture was diluted with DMAA (1.5 mL). The reaction mixture was then filtered through a syringe filter and analyzed by calibrated GC or by GC in combination with .sup.1H-NMR.

[0116] Analysis was done on an Agilent Technologies 6890N gas chromatograph with a split/splitless injector and an FID detector. The column used was an Agilent Technologies DB-1 capillary column (30 m*0.25 mm, 1 ?m) with Helium as carrier gas.

[0117] GC method: Split: 50/1, 2.0 mL/min, const. pressure, 80? C.-1 min-15? C./min-250? C.-5 min.

[0118] The measured GC signal areas, unless properly calibrated, are only supposed to be estimates due to overlapping of the starting material and the product. However, distinction between both species was clearly possible and supported by .sup.1H-NMR spectroscopy.

[0119] NMR analysis was done on a Magritek Spinsolve 60 Phosphorus Ultra NMR spectrometer with an .sup.1H frequency of 60 MHz. The samples were measured in non-deuterated DMAA as a solvent. Proton spectra were achieved with 4 scans, 6.4 sek acquisition time per scan, 30 sek repetition time and a pulse angle of 90?. Conversion to the viny compound was detected by the three characteristic proton resonances of the vinyl group.

Characteristic Example (Given in ppm)

[0120] .sup.1H-NMR (60 MHZ, DMAA) ?=6.85 (dd, .sup.3J.sub.HH=16.2 Hz, .sup.3J.sub.HH=9.5 Hz, 1H, NCH), 4.10 (d, .sup.3J.sub.HH=16.6 Hz, 1H, NCHCH.sub.2), 3.85 (d, .sup.3J.sub.HH=9.5 Hz, 1H, NCHCH.sub.2).

Autoclave Experiments:

[0121] ##STR00021##

(Premex Tall 2), Analysis by Calibrated GC

[0122]

TABLE-US-00004 # temperature conv./yield (sel.) A 110? C. 54%/40% (74%) B 120? C. 95%/73% (77%) C 130? C. 94%/71% (75%)

##STR00022##

Premex Tall 2, Analysis by GC

[0123] GC Area starting material/product: 81/19

##STR00023##

Premex Tall 2, Analysis by GC

[0124]

TABLE-US-00005 GC Area GC Area # Temp. Imidazole Vinylimidazole A 130? C. 91 9 B 140? C. 80 20 D 150? C. 65 35

##STR00024##

[0125] (Premex Tall 2), analysis by GC

TABLE-US-00006 GC GC Area Area # catalyst solvent Temperature Time MOX VMOX A 4 mol % neat 140? C. 16 h 77 23 B 4 mol % neat 150? C. 16 h 72 28 C 4 mol % neat 150? C. 60 h 66 34 D 5 mol % DMAA 140? C. 16 h 65 35 (2 equiv.) E 5 mol % DMAA 140? C. 16 h 45 55 (10 equiv.)

Experiments in Stainless Steel Autoclave at Elevated Acetylene Pressure (VMOX):

[0126] A 0.3-liter autoclave was charged with 100 g of 5-methyl-1,3-oxazolidin-2-one (MOX, 0.989 mol, 1 equiv.) and 16.3 g (0.0396 mol, 4 mol %) of trioctylphosphine (90%, technical grade) under inert atmosphere. The reactor was closed, filled with acetylene to 5 bar acetylene pressure, heated to 140? C. and then acetylene was passed through at 25 norm-liters/hour rate under the pressure of 17 bar for a reaction time of 16 hours. A norm-liter is one liter of a gas at 0? C. and 1013 millibar. The composition of the mixture obtained in the reactor after 16 hours of reaction was analyzed via gas chromatography and quantitative NMR.

##STR00025##

TABLE-US-00007 Content VMOX/MOX [g/100 g] Catalyst temperature Pressure Time GC VMOX GC MOX quantitative # [mol %] solvent [? C.] [bar] [h] [Area %] [Area %] .sup.1H-NMR A 4 Neat 140 17 16 69 2 58.3/N.A.

Experiments in Stainless Steel Autoclave at Elevated Acetylene Pressure (NVP):

[0127] A 0.3-liter autoclave was charged with 100 g of 2-pyrrolidinone (1.175 mol, 1 equiv.) and 7.3 g (0.018 mol, 1.5 mol %) of trioctylphosphine (90%, technical grade) under inert atmosphere. The reactor was closed, filled with nitrogen to 0.5 bar, heated to 140? C. and then filled with acetylene till 6.5 bar pressure in the reactor. The reactor pressure was kept at 6.5 bar by dosing acetylene during the course of the vinylation reaction. After the reaction was finished the reactor was cooled down to room temperature and depressurized. The composition of the mixture obtained in the reactor after 6 hours of reaction was analyzed via gas chromatography and quantitative NMR.

##STR00026##

TABLE-US-00008 Content NVP/2-Py [g/100 g] Catalyst temperature Pressure Time GC NVP GC 2-Py quantitative # [mol %] solvent [? C.] [bar] [h] [Area %] [Area %] .sup.1H-NMR A 2 neat 150 20 16 89 0, 6 N.A. B 1.5 neat 150 8 9 88 3 N.A. C 1.5 neat 150 6.5 6 85 3 84.9 ? 0.3/ 6.13 ? 0.15 D 1.5 neat 150 4.5 6 80 6 80.4 ? 0.1/ 9.41 ? 0.05