Regioselective microwave-assisted synthesis of substituted pyrazoles from ethynyl ketones

被引：57

作者：

Bagley, Mark C.

Lubinu, M. Caterina

Mason, Christopher

机构：

[1] Univ Cardiff Wales, Sch Chem, Cardiff CF10 3AT, Wales

[2] CEM Microwave Technol Ltd, Buckingham MK18 1WA, England

来源：

SYNLETT | 2007年 / 05期

基金：

英国工程与自然科学研究理事会;

关键词：

ethynyl ketones; pyrazoles; heterocycles; microwave synthesis; concurrent heating and cooling;

D O I：

10.1055/s-2007-970783

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Reaction of alpha,beta-ethynyl ketones and hydrazine derivatives gives 1,3- and 1, 5 -disubstituted pyrazoles in good yield. Microwave irradiation in concentrated hydrochloric acid-methanol (1.5% v/v), with concurrent cooling at sub-ambient temperatures or at 120 degrees C, for 30 or 2 minutes, respectively, facilitates rapid heterocyclization and preferentially gives the 1,3 -disubstituted regioisomer.

引用

收藏

页码：704 / 708

页数：5

相关论文

共 41 条

[1] The synthesis of novel heterocyclic substituted α-amino acids;: further exploitation of α-amino acid alkynyl ketones as reactive substrates [J].

Adlington, RM ;

Baldwin, JE ;

Catterick, D ;

Pritchard, GJ ;

Tang, LT .

JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, 2000, (15) :2311-2316

[2] The synthesis of pyrimidin-4-yl substituted α-amino acids.: A versatile approach from alkynyl ketones [J].

Adlington, RM ;

Baldwin, JE ;

Catterick, D ;

Pritchard, GJ .

JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1, 1999, (08) :855-866

[3] A simple continuous flow microwave reactor [J].

Bagley, MC ;

Jenkins, RL ;

Lubinu, MC ;

Mason, C ;

Wood, R .

JOURNAL OF ORGANIC CHEMISTRY, 2005, 70 (17) :7003-7006

[4] Iodine-catalysed Bohlmann-Rahtz cyclodehydration reactions [J].

Bagley, MC ;

Glover, C ;

Chevis, D .

SYNLETT, 2005, (04) :649-651

[5] Thiopeptide antibiotics [J].

Bagley, MC ;

Dale, JW ;

Merritt, EA ;

Xiong, A .

CHEMICAL REVIEWS, 2005, 105 (02) :685-714

[6] Microwave-assisted synthesis of pyrimidine libraries [J].

Bagley, MC ;

Hughes, DD ;

Lubinu, MC ;

Merritt, EA ;

Taylor, PH ;

Tomkinson, NCO .

QSAR & COMBINATORIAL SCIENCE, 2004, 23 (10) :859-867

[7] Stereoselective synthesis of the γ-lactam hydrolysate of the thiopeptide cyclothiazomycin [J].

Bagley, MC ;

Xiong, X .

ORGANIC LETTERS, 2004, 6 (19) :3401-3404

[8] New N-halosuccinimide-mediated reactions for the synthesis of pyridines [J].

Bagley, MC ;

Glover, C ;

Merritt, EA ;

Xiong, X .

SYNLETT, 2004, (05) :811-814

[9] Highly efficient synthesis of pyrimidines under microwave-assisted conditions [J].

Bagley, MC ;

Hughes, DD ;

Taylor, PH .

SYNLETT, 2003, (02) :259-261

[10] A facile solution phase combinatorial synthesis of tetrasubstituted pyridines using the Bohlmann-Rahtz heteroannulation reaction [J].

Bagley, MC ;

Dale, JW ;

Ohnesorge, M ;

Xiong, X ;

Bower, J .

JOURNAL OF COMBINATORIAL CHEMISTRY, 2003, 5 (01) :41-44

← 1 2 3 4 5 →