Flash vacuum pyrolysis. IX Thermal rearrangement of p-tolylcarbene to benzocyclobutene and styrene. A carbon-13 labeling study

1971 ◽  
Vol 93 (13) ◽  
pp. 3283-3285 ◽  
Author(s):  
E. Hedaya ◽  
M. E. Kent
Keyword(s):  
Thermal Rearrangement ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis

Methyleneketenes and methylenecarbenes. XII. Thermal rearrangement of acetylene

1978 ◽  
Vol 31 (3) ◽  
pp. 579 ◽  
Author(s):  
RFC Brown ◽  
FW Eastwood ◽  
GP Jackman
Keyword(s):  
Infrared Spectroscopy ◽  
Hydrogen Exchange ◽  
Spectral Studies ◽  
Intramolecular Rearrangement ◽  
Thermal Rearrangement ◽  
Mass Spectral ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis

Flash vacuum pyrolysis of 1,2,3,4-tetrafluoro-9-methoxy-9,10-dihydro- 9,10-ethenoanthracene[12-13C;10,12-D2], (600°) gives doubly labelled acetylene HC≡13CD. At temperatures of 700° and greater, the ethenoanthracene gives a mixture of HC≡13CD and DC≡13CH. Formation of the acetylene at 600° followed by pyrolysis at 850° confirmed that it is the free acetylene that undergoes intramolecular rearrangement: ����������������������������������� >700.����������������������������� HC≡13CD ↔ DC≡13CH The pattern of labelling in the acetylene was determined by allowing it to react with bromine and examining the resulting 1,1,2,2- tetrabromoethane by p.m.r. and infrared spectroscopy. Mass spectral studies on the tetrabromoethane showed that no significant intermolecular hydrogen exchange takes place up to 1050°.

Sulfonyl isocyanides RSO2NC

2017 ◽  
Author(s):  
Curt Wentrup ◽  
Horst Briehl
Keyword(s):  
Ir Spectrum ◽  
Reaction Conditions ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis

Flash vacuum pyrolysis (FVP) of 5-azido-1-aryltetrazoles results in triple N<sub>2</sub> elimination and formation of aryl isocyanides RNC, which rearrange in part to aroylnitriles RCN under the reaction conditions. Similar FVP of 5-azido-1-arenesulfonyltetrazoles generates a compound absorbing in the IR spectrum (77 K) at 2090 cm<sup>-1 </sup>and assigned the structure of arenesulfonyl isocyanide, ArSO<sub>2</sub>NC <b>11</b>. FVP at temperatures above 600 <sup>o</sup>C results in progressively more nitrile ArSO<sub>2</sub>CN <b>12</b>. Compound <b>11</b> also disappears on warming above -80 <sup>o</sup>C

Sulfonyl isocyanides RSO2NC

2017 ◽  
Author(s):  
Curt Wentrup ◽  
Horst Briehl
Keyword(s):  
Ir Spectrum ◽  
Reaction Conditions ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis

Flash vacuum pyrolysis (FVP) of 5-azido-1-aryltetrazoles results in triple N<sub>2</sub> elimination and formation of aryl isocyanides RNC, which rearrange in part to aroylnitriles RCN under the reaction conditions. Similar FVP of 5-azido-1-arenesulfonyltetrazoles generates a compound absorbing in the IR spectrum (77 K) at 2090 cm<sup>-1 </sup>and assigned the structure of arenesulfonyl isocyanide, ArSO<sub>2</sub>NC <b>11</b>. FVP at temperatures above 600 <sup>o</sup>C results in progressively more nitrile ArSO<sub>2</sub>CN <b>12</b>. Compound <b>11</b> also disappears on warming above -80 <sup>o</sup>C

The Pyrolytic Rearrangement of 1-Alkynoyl-3-methylpyrazoles: Synthesis of Pyrazolo[1,5-a]pyridin-5-ols and Related Compounds

1994 ◽  
Vol 47 (6) ◽  
pp. 991 ◽  
Author(s):  
RFC Brown ◽  
FW Eastwood ◽  
GD Fallon ◽  
SC Lee ◽  
RP Mcgeary
Keyword(s):  
Carbon Chain ◽  
Ring Structure ◽  
High Yield ◽  
Methyl Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis ◽  
Fused Ring ◽  
Related Compounds

Flash vacuum pyrolysis of 1-(alkyn-2′-oyl)-3-methylpyrazoles at 650°/0.03 mm forms pyrazolo[1,5-a]pyridin-5-ols, often in high yield, which may bear substituents at C2, C3 or C7. In the absence of a 3-methyl group in the precursor, N-ethynylpyrazoles are formed in low yield. The formation of both types of product is interpreted as involving 3-(N-pyrazolyl)propadienones formed by N1 → N2 migration of the N-alkynoyl group with inversion of the three-carbon chain. The fused-ring structure of 2-methylpyrazolo[1,5-a]pyridin-5-ol (25) was established by X-ray crystallography of the O-benzoyl derivative (27).

Preparation of benzocyclobutenes by flash vacuum pyrolysis

1978 ◽  
Vol 19 (46) ◽  
pp. 4569-4572 ◽  
Author(s):  
Peter Schiess ◽  
Markus Heitzmann ◽  
Suzanne Rutschmann ◽  
René Stäheli
Keyword(s):  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis

Enones with strained double bonds. 10. Use of flash vacuum pyrolysis to obtain bicyclo[3.3.1]non-1-en-3-one

1987 ◽  
Vol 52 (12) ◽  
pp. 2474-2481 ◽  
Author(s):  
Kay Ann Campbell ◽  
Herbert O. House ◽  
Bruce W. Surber ◽  
Walter S. Trahanovsky
Keyword(s):  
Double Bonds ◽  
Flash Vacuum Pyrolysis ◽  
Vacuum Pyrolysis
Sign in / Sign up

Export Citation Format

Share Document