Quaternization and dequaternization of pyrazoles in solvent-free conditions:: Conventional heating versus microwave irradiation

被引：8

作者：

Díez-Barra, E ^{[1
]}

de la Hoz, A

Sánchez-Migallón, A

Elguero, J

机构：

[1] Univ Castilla La Mancha, Fac Quim, Dept Quim Organ, E-13071 Ciudad Real, Spain

[2] CSIC, Inst Quim Med, E-28006 Madrid, Spain

来源：

JOURNAL OF HETEROCYCLIC CHEMISTRY | 1999年 / 36卷 / 04期

关键词：

D O I：

10.1002/jhet.5570360410

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

We report a study on the quaternization and dequaternization of pyrazoles by conventional heating and microwave irradiation in solvent-free conditions. Microwave irradiation produces an acceleration in the quaternization rate and a rapid equilibration between quaternized and non quaternized products. Dequaternization is also more rapid and a change on the selectivity is observed using symmetric pyrazolium salts.

引用

页码：889 / 894

页数：6

共 25 条

[1]

ABENHAIM D, 1994, HETEROCYCLES, V38, P793

[2] Alkylation and arylation of pyrazoles under solvent-free conditions:: Conventional heating versus microwave irradiation [J].

Almena, I ;

Díez-Barra, E ;

de la Hoz, A ;

Ruiz, J ;

Sánchez-Migallón, A ;

Elguero, J .

JOURNAL OF HETEROCYCLIC CHEMISTRY, 1998, 35 (06) :1263-1268

[3]

ARANDA RMM, 1994, CATAL LETT, V25, P3

[4] ALKYLATION, ACYLATION AND SILYLATION OF AZOLES [J].

BEGTRUP, M ;

LARSEN, P .

ACTA CHEMICA SCANDINAVICA, 1990, 44 (10) :1050-1057

[5]

Behr L.C., 1967, PYRAZOLES PYRAZOLINE

[6] Remarkable fast n-alkylation of azaheterocycles under microwave irradiation in dry media [J].

Bogdal, D ;

Pielichowski, J ;

Jaskot, K .

HETEROCYCLES, 1997, 45 (04) :715-722

[7] REGIOSELECTIVE ADAMANTYLATION OF N-UNSUBSTITUTED PYRAZOLE DERIVATIVES [J].

CABILDO, P ;

CLARAMUNT, RM ;

FORFAR, I ;

ELGUERO, J .

TETRAHEDRON LETTERS, 1994, 35 (01) :183-184

[8] BASICITY OF AZOLES .2. THEORETICAL-STUDY OF THE BASICITY OF METHYLPYRAZOLES AND METHYLIMIDAZOLES [J].

CATALAN, J ;

ELGUERO, J .

JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2, 1983, (12) :1869-1874

[9]

Coxon J. M., 1994, ADV DET R M, V3, P199

[10] SYNTHESIS OF N-ALKYLPYRAZOLES BY PHASE-TRANSFER CATALYSIS WITHOUT SOLVENT [J].

DIEZBARRA, E ;

DELAHOZ, A ;

SANCHEZMIGALLON, A ;

TEJEDA, J .

SYNTHETIC COMMUNICATIONS, 1990, 20 (18) :2849-2853

← 1 2 3 →