Acylation and alkylation reactions. Part V. Some syntheses of tricyclic derivatives of benzo[b]furan-3(2H)-one

Alkylation reactions of (E)-11-(3-methylaminopropylidene)-6,11-dihydrodibenzo[b,e]thiepin (II) with alkyl bromide, propargyl bromide, 2-chloroethanol, 1-chloropropan-2-ol and 3-chloropropanol gave the N-substituted derivatives III - VII. Acylation of amino alcohols V - VII with acetyl chloride and decanoyl choride resulted in the esters VIII - XI. 6,11-Dihydrodibenzo[b,ethiepin-11-carboxylic acid was transformed via the acid chloride to the amide XIV. Out of the compounds prepared, only the amino alcohols V- VII and the ester VIII revealed in pharmacological tests the activity similar to that of tricyclic antidepressants; their activity is lower than that of prothiadene (I). The decanoates IX - XI are devoid of antireserpine activity; the attempt at finding long-acting depot antidepressant agents in this way was thus unsuccessful. The amide XIV has mild anticonvulsant activity.

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Lone-pair cooperativity in the N-alkylation of some derivatives of 2,2'-biimidazole

Australian Journal of Chemistry ◽

10.1071/ch9812569 ◽

1981 ◽

Vol 34 (12) ◽

pp. 2569 ◽

Cited By ~ 7

Author(s):

LW Deady

Keyword(s):

Steric Hindrance ◽

Alkylating Agent ◽

Alkylating Agents ◽

Lone Pair ◽

Lone Pairs ◽

Close Proximity ◽

Alkylation Reactions ◽

Rate Ratios ◽

Derivatives Of

The relative rates of N-alkylation of 1,1'-dimethyl-2,2'-biimidazole (6), 5,6-dihydrodiimidazo- [1,2-a:2',1'-c]pyrazine (7) and 6,7-dihydro-5H-diimidazo[l,2-a:2',1'-c][l,4]diazepine (8) with a variety of alkylating agents are reported. Irrespective of the alkylating agent, the order of reactivity was (8) (where the biimidazole has an additional three-carbon bridge) > (7) (two-carbon bridge) > (6) (no bridge), with a maximum of (8)/(6) = 317 for reaction with chloro(methoxy)methane. Since reaction of (8) is most susceptible to steric hindrance, but where the nitrogen lone pairs are in close proximity, these results support the idea of lone-pair cooperativity in the alkylation reactions. Variation in the rate ratios with changes in alkylating agent are discussed.

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11,13-Methylenation of sesquiterpene exomethylene-γ-lactones: Synthesis of sesquiterpene cyclopropyl-γ-lactones

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19911052 ◽

1991 ◽

Vol 56 (5) ◽

pp. 1052-1063 ◽

Cited By ~ 3

Author(s):

Giovanni Appendino ◽

Elisabetta Ghilardi ◽

Giancarlo Cravotto ◽

Pierluigi Gariboldi

Keyword(s):

Comparative Study ◽

Silica Gel ◽

Good Yield ◽

Alternative Methods ◽

Basic Alumina ◽

Alkylation Reactions ◽

Derivatives Of

11,13-Methylene derivatives of sesquiterpene exomethylene-γ-lactones were prepared by reaction of diazomethane and photolysis of the resulting pyrazoline adduct(s). Variable amounts of exomethylene- and ethylidene-γ-lactones were also formed in the photolysis reaction. These compounds could bee removed after reaction with diethylamine and chromatography on a bilayer (basic alumina/silica gel) column. Also 11,13-methylene derivatives of acid-and thermolabile germacranolides could be prepared in good yield with this procedure. Results obtained using alternative methods of methylenation are reported. A comparative study of the reactivity towards nucleophiles of exomethylene- and cyclopropyl sesquiterpene-γ-lactones provided little support for the involvement of compounds of the latter class in in vivo alkylation reactions.

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