piperine can be isolated from pepper and converted to piperic acid.
over 130 years ago (!) in 1869 fittig mielck described very detailed
[1](page 47-56) the cleavage of piperic acid to a compund they called
mono-bromo-piperonal. they wrote: "the preparation of this compund is
extremely easy and we obtained it each time in considerable quantity ..."
they used for the simple preparation: bromine, Na2CO3 and alcohol.
furthermore they performed extensive investigations on this compund,
beside other results, they found that mono-bromo-piperonal is extremely
easy volatile with steam, insoluble in cold water and sparsely in boiling
water. it crystallizes from alcohol in long, bendable and completely
colorless and glittery needles and melts at 129°C to a colorless liquid.
the molecular formula is C8H5BrO3.
[1] analen der chemie und pharmacie, 1869 152, 25-58
"untersuchungen ueber die constitution des piperins
und seiner spaltproducte piperinsaeure und piperidin"
rud fittig, w h mielck
in the paper are no particulars about the structure of mono-bromo-piperonal.
but piperonal has only 3 possible positions for a ring substitution
with bromine. so lets see what the internet nowadays knows about this
compund:
6-bromo-piperonal
=================
Molecular Formula: C8H5BrO3
Molecular Weight: 229.03
CAS Number: 15930-53-7
Air sensitive, Store under nitrogen
Melting Point (°C): 128 to 132
6-BROMO-1,3-BENZODIOXOLE-5-CARBOXALDEHYDE
=========================================
Molecular Formula: C8H5BrO3
CAS Number: 15930-53-7
[
http://www.sigmaaldrich.com/
]

[
http://www.interchim.com/interchim/chemical/combinatorial_chemistry/hetero/otherheterocycles5.htm
]
BINGO !!!
so it looks like
mono-bromo-piperonal and
6-bromo-piperonalare the same.
and 6-bromo-piperonal again is a precursor for:
MMDA-2
(
http://www.erowid.org/library/books_online/pihkal/pihkal133.shtml)