Ethyl 4-broMopyrazolo[1,5-a]pyridine-3-carboxylate synthesis
- Product Name:Ethyl 4-broMopyrazolo[1,5-a]pyridine-3-carboxylate
- CAS Number:55899-29-1
- Molecular formula:C10H9BrN2O2
- Molecular Weight:269.09
626-55-1
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623-47-2
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55899-29-1
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![Ethyl 6-broMopyrazolo[1,5-a]pyridine-3-carboxylate](/CAS/20150408/GIF/55899-30-4.gif)
55899-30-4
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$157.00/1/ G
Yield:55899-30-4 29% ，55899-29-1 29%
Reaction Conditions:
Stage #1: 3-Bromopyridinewith mesitylenesulfonylhydroxylamine in dichloromethane at 0; for 2 h;
Stage #2: propynoic acid ethyl esterwith potassium carbonate in N,N-dimethyl-formamide at 20; for 18 h;
Steps:
4.1.1. Synthesis of ethyl pyrazolo[1,5-a]pyridine-3-carboxylates 3
General procedure: These were made using MSH or DNPH as detailed below, unless otherwise stated. A fresh solution of MSH23 in CH2Cl2 (1 equiv) was added to the substituted pyridine (1 equiv) in CH2Cl2 (10 mL) at 0 °C. After 2 h, the solvent was removed in vacuo. Alternatively, a solution of DNPH12 (1 equiv) and the substituted pyridine (1 equiv) in MeCN (40 mL) was heated at 40 °C for 18 h. The solvent was removed in vacuo. The method continues by taking the residue from either method in dry DMF (8 mL), and then ethyl propiolate (1 equiv) and K2CO3 (2 equiv) were added, and the suspension stirred at room temperature for 18 h. The reaction mixture was diluted with water and extracted twice with EtOAc. The combined organic phases were washed three times with water then with brine, dried (Na2SO4) and the solvent removed in vacuo. Chromatography (eluting with a hexanes: EtOAc gradient, unless otherwise stated) gave the pyrazolo[1,5-a]pyridine.
References:
Kendall, Jackie D.;O'Connor, Patrick D.;Marshall, Andrew J.;Frédérick, Rapha?l;Marshall, Elaine S.;Lill, Claire L.;Lee, Woo-Jeong;Kolekar, Sharada;Chao, Mindy;Malik, Alisha;Yu, Shuqiao;Chaussade, Claire;Buchanan, Christina;Rewcastle, Gordon W.;Baguley, Bruce C.;Flanagan, Jack U.;Jamieson, Stephen M.F.;Denny, William A.;Shepherd, Peter R. [Bioorganic and Medicinal Chemistry,2012,vol. 20,# 1,p. 69 - 85] Location in patent:experimental part
55899-13-3
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623-47-2
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55899-29-1
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55899-30-4
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$157.00/1/ G
197376-41-3
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55899-29-1
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