7128-53-2

Upstream product

• 70354-71-1 (+/-)-eseroline 
• 408340-83-0 eseroline 
• 624-83-9 methyl isocyanate 
• 18342-66-0 2,5-dioxopyrrolidin-1-yl methylcarbamate 
• 46479-70-3 (+/-)-5-methoxy-3a,8-dimethyl-1,2,3,3a,8,8a-hexahydropyrrolo[2,3-b]indole 
• 2291-51-2 (5-methoxy-1,3-dimethyl-2-oxo-2,3-dihydro-1H-indol-3-yl)acetonitrile 
• 2731-01-3 (±)-5-methoxy-1,3a,8-trimethyl-1,2,3,3a,8,8a-hexahydropyrrolo-[2,3-b]indole 
• 150-75-4 N-methyl-p-aminophenol 
• 1010-68-0 1,3-dimethyl-5-hydroxyoxindole 
• 161986-95-4 4-hydroxy-N-methyl-N-(α-bromopropionyl)aniline 
• 161467-02-3 1,3-dimethyl-5-tetrahydropyranyloxyoxindole 
• 161986-97-6 1,3-dimethyl-3-cyanomethyl-5-tetrahydropyranyloxyoxindole 
• 116707-99-4 1,3-dimethyl-5-methoxyindolin-2-one 
• 143947-74-4 5-methoxy-1,3-dimethyl-3-(2-methylamino-ethyl)-indolin-2-one 

Relevant academic research and scientific papers

Metal-Free Synthesis of Oxazolidine-2,4-diones and 3,3-Disubstituted Oxindoles via ICl-Induced Cyclization

A metal-free method for the construction of oxazolidine-2,4-diones and oxindoles was discussed. Using iodine monochloride (ICl) as both the reaction promoter and iodide source, the iodolactonization of N-Boc acrylamides proceeded readily and provided the corresponding iodo oxazolidine-2,4-diones and oxazolidin-2-ones in good isolated yields. The obtained oxazolidine-2,4-diones can be used as key intermediates in the synthesis of toloxatone. When N-alkyl-N-arylacrylamide derivatives were subjected to the same reaction, iodocarbocyclization products 3,3-disubstituted oxindoles were obtained. The obtained oxindoles can be used as key intermediates in the synthesis of the alkaloids (±)-esermethole and (±)-physostigmine.

Palladium-catalyzed enantioselective domino heck-cyanation sequence: Development and application to the total synthesis of esermethole and physostigmine

An efficient synthesis of functionalized 3-alkyl-3-cyanomethyl-2-oxindole 1 by a palladium-catalyzed domino Heck-cyanation reaction has been developed. Reaction of ortho-iodoanilide 5 with potassium ferro(II)cyanide, K 4[Fe(CN)6], dissolved in DMF in the presence of palladium acetate and sodium carbonate afforded oxindole 1 in good to excellent yields. An enantioselective domino Heck-cyanation process has been developed for the first time using (S)-DIFLUORPHOS as a chiral supporting ligand, and an enantioselectivity of up to 79% ee in the enantiomerically enriched oxindole was obtained under optimized conditions. A concise total synthesis of esermethole and physostigmine, powerful inhibitors of acetyl- and butyryl-cholinesterase, is documented.

TOTAL SYNTHESIS OF RACEMIC PHYSOSTIGMINE, PHYSOVENINE AND ITS SULFUR ANALOGUE BY THE OXINDOLE-5-O-TETRAHYDROPYRANYL ETHER ROUTE

1,3-Dimethyl-5-tetrahydropyranyloxyoxindole (4) was synthesized from 4-methylaminophenol sulfate (metol) (1).Phase transfer catalyzed C3-alkylation of compound (4) produced alcohol (5), nitrile (8), and thioalkohol (13) after treatment of bromide (12) with thiourea.Compound (5) and (13) were converted into racemic physovenine (7) and thiaphysovenine (15) by reaction with LAH, in situ deprotection, and reaction of phenols with methyl isocyanate.Conversion of nitrile (8) into racemic physostigmine (11) which included a reductive N-methylation of 9 was similarly accomplished.

The enantioselective synthesis of (-)-physostigmine via chiral sulfoxides

The total synthesis of naturally occurring (-)-physostigmine is described. The key element for the asymmetric induction is the chirality transfer from optically active 2-(alkylsulfmyl)indoles to indoline butyrolactones bearing two chiral centers. Novel features of this synthesis involve the use of a new class of sulfoxylating agents, N-(alkylsulfinyljoxazolidinones, to prepare the starting indolyl sulfoxides and the correlation of the size of the alkyl group on the sulfoxide with the degree of asymmetric induction. The overall synthesis requires a dozen steps from commercially available 5-(benzyloxy)indole.

2-Azonianorbornene-2-spiro-1'-aziridinium triflate - A novel ethylene immonium ion equivalent: Application to a synthesis of physostigmine

A unique protocol for either the aminoethylation or the N-methyl aminoethylation of carbonyl compounds featuring the preparation and use of a novel spiroaziridinium salt, 2-azonianorbornene-2-spiro-1'-aziridinium triflate 2, is described.

Rapid Syntheses of Some Indole Alkaloids of the Calabar Bean

A rapid, efficient route to 3,3-disubstituted oxindoles from o-iodo anilines has been developed.It involves the cyclisation of the corresponding fumarate amides 4 and 15 with butyllithium at -100 deg C in the presence of an excess of trimethylchlorosilane.An X-ray crystal structure of 4 suggests that the speed and efficiency of this intramolecular Michael addition is dependent on the conformation adopted by 4 which is particularly suitable for the reaction.This method has been applied to the synthesis of the alkaloids physovenine, physostigmine and esermethole in very high overall yields.