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The Hive => Newbee Forum => Topic started by: Daphuk_up on April 28, 2004, 05:48:00 PM

Title: Grignard and 2C-B
Post by: Daphuk_up on April 28, 2004, 05:48:00 PM

quick hit pure curiosity question (no search engine to satisfy monkey urges):

Will 2c-b form a grignard reagent (specific to the aromatic bromine)?  Will dripping an ethereal solution of 2c-b into the grignard addition product of ethyl bromide produce 2c-e?

Thanks. :)

EDIT: Found that grignard reagents react with nitriles, but what about terminal nitrogens saturated with either hydrogen or oxygen?  (ie, 2c-b or 4-bromo-2,5-dimethoxy-nitroethane?)  SWID is unsure if the double carbon bond in a styrene would have any effect or not.

Title: Grignard incompabilities
Post by: Rhodium on April 29, 2004, 06:45:00 AM

Will 2c-b form a grignard reagent (specific to the aromatic bromine)?  Will dripping an ethereal solution of 2c-b into the grignard addition product of ethyl bromide produce 2c-e?

No and no. The grignard reagent is incompatible with the amine.

Found that grignard reagents react with nitriles, but what about terminal nitrogens saturated with either hydrogen or oxygen?  (ie, 2c-b or 4-bromo-2,5-dimethoxy-nitroethane?)  SWID is unsure if the double carbon bond in a styrene would have any effect or not.

Grignard reagents can usually not be made from compounds containing any of the following groups: nitriles, acids, carbonyl functions (ketone/aldehyde/ester/amide/anhydride) and any functional group containing -NO₂, -OH, -SH, or -NH groups.

Title: SWID thanks you for the clarification.
Post by: Daphuk_up on April 29, 2004, 10:23:00 PM

SWID thanks you for the clarification.  :)

He supposes the best route then would be:
1. monobromination of 2,5-dimethoxybenzene
2. grignard reaction with ethyl bromide
3. gatterman formylation
4. subsequent condensation with nitromethane and reduction(s) to afford phenethylamine

Title: 2,5-dimethoxybromobenzene grignard
Post by: Rhodium on April 30, 2004, 07:19:00 AM

Regarding the formation of 2,5-dimethoxybromobenzene grignard, read the following:

https://www.thevespiary.org/rhodium/Rhodium/chemistry/2cbde.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/2cbde.html)

Post 354784 (https://www.thevespiary.org/talk/index.php?topic=12028.msg35478400#msg35478400)

(Rhodium: "Tips & Tricks regarding dimethoxybenzene Grignards", Novel Discourse)