Pyrrole alkylation

Pyrrolenines are formed by the alkylation of the Grignard derivatives of polyalkylated pyrroles. Alkylation occurs at positions 2 and 3, although the former predominates. Pyrrolenines readily undergo further alkylation to give quaternary salts (Scheme 87). 

Animal glue HMDS Pyrrole, alkyl pyrroles, benzeneacetonitrile and benzenepropanenitrile 28... 

Pyrrole, alkyl pyrroles, benzeneacetonitrile and benzenepropanenitrile. Pyrolyser continuous mode micro furnace pyrolysing injection system Pyrojector (SGE, Austin, Texas, USA) furnace pressure 14 psi purge flow 0.5 ml min 1 [28],... 

Pyrrole Alkylating agent Method Reaction times" % yield... 

Pyrroles give polyalkylated products on reaction with methyl iodide at elevated temperatures and the more reactive ally and benzyl halides under milder conditions in the presence of weak bases. Alkylation of pyrrole Grignard reagents gives mainly 2-alkylated pyrroles whereas A-alkylated pyrroles are obtained by alkylation of pyrrole alkali metal salts in ionizing solvents (see Section 3.3.1.3.1). Pyrrolenines are formed by the C-alkylation of the Grignard derivatives of polyalkylated pyrroles. Alkylation occurs at positions 2 and 3, although the former predominates. 

Indoles can be 3-alkylated by allyl alcohols in the presence of lithium perchlorate and acetic acid 101 is an example (Scheme 42). Pyrrole -alkylation can be achieved with simple alkyl halides [1-bromopentadecane, l-(bromomethyl)-, l-(3-chloropropyl)- and l-(3-iodopropyl)benzenes, 2-(2-bromoethyl)- and 2-(3-bromopropyl)naphthalenes] and mesylates [3-phenylpropyl-, l-methyl-3-phenylpropyl-, 2-(2-naphthyl)ethyl- and 3-(2-naphthyl)propyl methanesulfonates] selectively at C(2) and C(5) positions via reaction in various ionic liquids (e.g., Scheme 43) <20050L1231>. 

Table 1. Important porphyrins of the ETIO-type (/ -pyrrolic alkyl substituents,...

Han X, Wu J (2013) Redox chain reaction-indole and pyrrole alkylation with unactivated secondary alcohols. Angew Chem Int Ed 52(17) 4637-4640... 

Products of Pyrroles Alkylation by Functional Organic Halides... 

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