Studies on the Doebner-Miller, Skraup, and Related Reactions. II. Preparation and Cyclization of 4-(2'-Nitroanilino)-3-methylbutan-2-one

1963 ◽  
Vol 16 (5) ◽  
pp. 828 ◽  
Author(s):  
GM Badger ◽  
BC Ennis ◽  
WE Matthews

The intermediate adduct (e.g. III) formed in Skraup and Doebner-Miller reactions has the nature of a Mannich base. It has now been prepared from o-nitroaniline, formaldehyde, and methyl ethyl ketone by the Mannich reaction. It has been cyclized to 3,4-dimethyl-8-nitroquinoline under acidic oxidizing conditions; but it is not cyclized by neutral oxidants, nor by non-oxidizing acids or Lewis acids.

2016 ◽  
Vol 71 (11) ◽  
pp. 1147-1157 ◽  
Author(s):  
Elsayed M. Afsah ◽  
Saad S. Elmorsy ◽  
Soha M. Abdelmageed ◽  
Zaki E. Zaki

AbstractThe hydrazide-hydrazones 6a–d and 7a, b were obtained by treating isatin (1) or its Mannich base 2 with hydrazides incorporating piperidine, morpholine, and piperazine units. The reaction of 1 and 2 with hydrazides related to triazenes having piperidine, morpholine, and 1,2,3,4-tetrahydroisoquinoline moieties gave 12a–c and 13a–c. Treatment of 1 and 2 with iminodiacetohydrazide (14) and ethylenediamine tetraacetohydrazide (18) afforded 15–17 and 19a, b, respectively. The Mannich reaction of the Schiff base 20 with formaldehyde and the appropriate hydrazide or bis(hydrazide) gave 21a, b and 22a, b. The hydrazides related to Schiff bases 20 and 26 were used as precursors in synthesis of compounds incorporating two 2-oxoindoline units or formazan moiety.


2006 ◽  
Vol 61 (4) ◽  
pp. 486-494 ◽  
Author(s):  
Kerstin Bischoff ◽  
Ulrich Girreser ◽  
Dieter Heber ◽  
Martin Schütt

The Mannich reaction of 7-aryl-5,6-dihydropyrido[2,3-d]pyrimidines 3, easily accessible by condensation of 6-amino-1,3-dimethyluracil (1) with Mannich bases 2a - c, gives rise to a mixture of 7-aryl-6-(N,N-dimethylaminomethyl)pyrido[2,3-d]pyrimidines 6 and 7 as well as 1,2-bis- (7-arylpyrido[2,3-d]pyrimidin-6-yl)ethane 13 the ratio of which depends on the reaction conditions and the amine used. 6-Alkylamino-1,3-dimethyluracils 15 - 18 were converted to the corresponding 5-(3-oxo-3-phenylpropyl)uracils 19 - 22 by condensation with the Mannich base 2a. Ring closure of 19 - 22 was performed by Vilsmeier formylation to afford the 8-alkyl- and 7,8-diaryl-5,8- dihydropyrido[2,3-d]pyrimidine-6-carbaldehydes 9 - 12 via the corresponding iminium salts 27 - 30


1982 ◽  
Vol 35 (7) ◽  
pp. 1421 ◽  
Author(s):  
ML Bolte ◽  
WD Crow ◽  
S Yoshida

Problems associated with earlier synthetic approaches to the G-regulators have been overcome by the use of the Mannich reaction in aprotic media. Under these conditions the Mannich base formed from the reaction of 1,3-diketones and aldehydes is stabilized by internal hydrogen bonding and can be isolated in high yield. In aqueous acid rapid elimination occurs to give the 2-methylene 1,3-diketones, which first enolize then add oxygen to generate the G-regulator structure. The steric limitations of the reactions are examined.


2014 ◽  
Vol 34 (1) ◽  
pp. 243-250
Author(s):  
Jianghong DING ◽  
Le XU ◽  
Hao XU ◽  
Haihong WU ◽  
Yueming LIU ◽  
...  

2004 ◽  
Vol 15 (7) ◽  
pp. 365-369 ◽  
Author(s):  
Belkıs Ustamehmetoğlu ◽  
A. Sezai Saraç ◽  
Nilgün Kızılcan ◽  
Ahmet Akar

RSC Advances ◽  
2021 ◽  
Vol 11 (16) ◽  
pp. 9098-9111
Author(s):  
Salahudeen Shamna ◽  
C. M. A. Afsina ◽  
Rose Mary Philip ◽  
Gopinathan Anilkumar

Amino alkylation of an acidic α-proton of a carbonyl by formaldehyde and a primary/secondary amine or ammonia, affording a β-amino-carbonyl compound also known as a Mannich base is a valuable reaction. We focus on recent advances in Zn catalysed Mannich reactions.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3317
Author(s):  
Maria Carolina Pereira Gonçalves ◽  
Jéssica Cristina Amaral ◽  
Roberto Fernandez-Lafuente ◽  
Ruy de Sousa Junior ◽  
Paulo Waldir Tardioli

In this paper, we have performed the Lipozyme 435-catalyzed synthesis of xylose oleate in methyl ethyl ketone (MEK) from xylose and oleic acid. The effects of substrates’ molar ratios, reaction temperature, reaction time on esterification rates, and Lipozyme 435 reuse were studied. Results showed that an excess of oleic acid (xylose: oleic acid molar ratio of 1:5) significantly favored the reaction, yielding 98% of xylose conversion and 31% oleic acid conversion after 24 h-reaction (mainly to xylose mono- and dioleate, as confirmed by mass spectrometry). The highest Lipozyme 435 activities occurred between 55 and 70 °C. The predicted Ping Pong Bi Bi kinetic model fitted very well to the experimental data and there was no evidence of inhibitions in the range assessed. The reaction product was purified and presented an emulsion capacity close to that of a commercial sugar ester detergent. Finally, the repeated use of Lipozyme 435 showed a reduction in the reaction yields (by 48 and 19% in the xylose and oleic acid conversions, respectively), after ten 12 h-cycles.


Sign in / Sign up

Export Citation Format

Share Document