The 2,5-bis(phosphinoylmethyl)-thiophenes
[(Oct)(EtO)P(O)CH
$_{2}$
]
$_{2}$
C
$_{4}$
H
$_{2}$
S
and
[(Ph)(EtO)P(O)CH
$_{2}$
]
$_{2}$
C
$_{4}$
H
$_{2}$
S
are obtained from the appropriate phosphites, RP(OEt)
$_{2}$
(R=Oct, Ph) and
(BrCH
$_{2})_{2}$
C
$_{4}$
H
$_{2}$
S
by using Arbusov reaction conditions. The analog
[(Oct)
$_{2}$
P(O)CH
$_{2}$
]
$_{2}$
C
$_{4}$
H
$_{2}$
S
is more conveniently obtained via the reaction of the phosphono-Grignard
reagent (Oct)
$_{2}$
P(O)MgBr and
(BrCH
$_{2})_{2}$
C
$_{4}$
H
$_{2}$
S.
An improved alternate Arbusov synthesis of the known
[Ph
$_{2}$
P(O)CH
$_{2}$
]
$_{2}$
C
$_{4}$
H
$_{2}$
S
is described along with its conversion to
[Ph
$_{2}$
P(S)CH
$_{2}$
]
$_{2}$
C
$_{4}$
H
$_{2}$
S
via Lawesson chemistry. The new compounds are characterized by MS, IR and NMR
methods, and the molecular structures of
[Ph
$_{2}$
P(O)CH
$_{2}$
]
$_{2}$
C
$_{4}$
H
$_{2}$
S
and
[Ph
$_{2}$
P(S)CH
$_{2}$
]
$_{2}$
C
$_{4}$
H
$_{2}$
S
have been confirmed by single crystal X-ray diffraction methods.
