# US 4,393,218 A · 2,2,4,5,5-Pentamethyl-3-formyl-.DELTA..sup.3 -pyrroline and the preparation thereof

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- Number: US 4,393,218 A
- Document ID: US4393218A
- Status: Granted
- Kind: A
- Application number: 06/327,753
- Filed: 1981-12-07
- Granted: 1983-07-12
- Earliest claimed: 1979-05-29
- Assignees: Anic S.p.A.
- Inventors: Silvestro Costanzi; Francesco Tessarolo; Maurizio Brunelli
- Web page: https://patentgrep.com/patent/US4393218A

## CPC

- C07D 207/08: with hydrocarbon radicals, substituted by hetero atoms, attached to ring carbon atoms
- C07D 207/20: with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to ring carbon atoms
- C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08)

## Abstract

A process for preparing 2,2-dialkyl-4-methyl-5,5-dialkyl-3-formyl-.DELTA..sup.3 -pyrrolines by reacting the corresponding dialkyl substituted di-tert-propargylamines with water at a pH equal to or less than 3.0. Preferably, an inorganic mercury compound is used as a catalyst.

## Claims

### Claim 1

The compound, 2,2,4,5,5-pentamethyl-3-formyl-.DELTA..sup.3 -pyrroline.

### Claim 2 (depends on 1)

A process for the preparation of the compound of claim 1 which comprises reacting di-tert-propargylamine at a pH equal to or less than 3 in an environment comprising from 60 to 65% of sulfuric acid, based on the total solution, at a temperature of between 120.degree. and 135.degree. C.

### Claim 3 (depends on 1)

A process for the preparation of the compound of claim 1 which comprises reacting di-tert-propargylamine at a pH equal to or less than 3 in an environment comprising between 45 and 50% of sulfuric acid and between 0.6 and 0.7% of mercury oxide, based on the total solution, at a temperature between 100.degree. and 115.degree. C.