
TY  - JOUR
A1  - Brown, RFC 
A1  - Eastwood, FW 
A1  - Fallon, GD 
A1  - Lee, SC 
A1  - Mcgeary, RP 
T1  - The Pyrolytic Rearrangement of 1-Alkynoyl-3-methylpyrazoles: Synthesis of Pyrazolo[1,5-a]pyridin-5-ols and Related Compounds
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1994
VL  - 47
IS  - 6
SP  - 991
EP  - 1007
KW  - 
UR  - https://doi.org/10.1071/CH9940991 
N2  - Flash vacuum pyrolysis of 1-(alkyn-2&#8242;-oyl)-3-methylpyrazoles at 650&#176;/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 &#8594; 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). 
ER  -

