Safrole from salicylic aldehyde

Dr. Weird · Mon Apr 18, 2005 6:44 am

wait a second i gotta correct myself a lil' i went cross-eyed. Forget the darn salicylicaldyde since itz cheaper/easier to just get your pyrocatchol already made. Can you methylenate it to 1,2-methylenedioxybenzene aka 1,3-benzodioxole and then just get those 3 carbons and 4 hydrogens to get on there??
1,3-benzodioxle -- C₇ H₆ O₂
safrole --C₁₀ H₁₀ O₂

Dr. Weird · Mon Apr 18, 2005 6:57 am

what are u talking about?? That's what I said. I was saying indole amine put it wrong since pryocatechol is 1,2-dihydroxybenzene not 1,3 saying maybe because he meant to say 1,2-methylenedioxybenzene, it has a synonym 1,3-benzodioxole and not 1,3-methylenedioxybenzene. Got me so far?? by adding the allyl group you get your safrole has a synonym 5-allyl-1,3benzodioxole, got it now??

The 3,4-Methylenedioxybenzaldehyde aka 1,3-benzodioxole-5-carbaldehyde is also know as piperonal which is what indole said you end up with. brain aksed how to obtain 3,4-methylenedioxybenzene but I think meant to put safrole (with the allyl). I got lost cuz of naming errors and I get blamed.
good grief Rolling Eyes

p.s. after reading this go back and read my previous post again and see i got it right

Dr. Weird · Mon Apr 18, 2005 8:34 am

Reading thru rhodium here is what I found
1. pyrocatechol is reacted in a basic solution (NaOH) with dibromomethane (CH2Br2) to 1,2-methylenedioxybenzene
2. The 1,2-methylenedioxybenzene is selectively brominated with N-bromosuccinimide to form 4-bromo-1,2-methylenedioxybenzene.
3. The 4-bromo-1,2-methylenedioxybenzene is reacted with Mg to give the Grignard adduct (R-MgBr), and coupled with allyl bromide to form safrole.

No mention of going thru 3,4-methylenedioxybenzene.

nyarlothotep · Mon Apr 18, 2005 8:42 am

once the allyl chain is added to the 4-bromo position, the numbering switchs and it becomes 3,4 methylene dioxy.
The first reaction you've stated creates the 3,4 methylenedioxy compound, just under a different IUPAC name.

nubee · Master Archiver

there is also info in this book about Salicyclic Acid, but i figured it was not needed due to above...but can be posted if wanted

scanned from the book: "A Short Organic Chemistry - F. Sherwood Taylor - 1948", which i picked up at a second hand book store for 8$

here's some more related scans:
(it seems it ma be possible to go straight from phenol to pyrocatechol...)

so how does this help... Question

Dr. Weird · Tue Apr 19, 2005 3:56 am