S o Ta h
172
111111
i
1.
January 196s
173
NOTES
studied. aiid in one sequence a novel preparation of to his brought about the elimination of p-toluenesuloxazepam ha. been achieved. finic acid to afford a mixture of compounds from which Proctor and others*-j have studied the base-catalyzed the desired IX as well as the already linown compound elimination of the sulfinate anion from variously X6,’was isolated. wbstituted iulfonamides to afford imines. For exThe nmr spectrum of IX was consistent with the ample. 3.G-dihydro-5-p-tolylsulfonyl-7H-dibenz [b,d]assigned structure. Two doublets resulting from alazepin-i-one (IT) ivith sodium ethoside at room temlylic coupling betiyeen the 3-proton and the 5-proton perature gave SH-dibenz[b,d]azepin-7-one (T’I). I n occur at 6 5.7s and 6.58 ( J = 2 cps). I n contrast, the order to apply this method t o the preparation of a isomeric X shows a singlet at 6 4.22 for its 3-protons. 1,,5-dihydro-2HH-l ,4-benzodiazepiii-2-one, it n as neeRecovery of the original starting material T’II by recssary t o prepare a 4-p-tolylsulfori~l-l,3,4,5-tetrahydroduction of IX with tetraethylammonium borohydride demonstrated the preservation of the 1.4-benzodiazepine ring. Compound IX was isomerized to X by NHMe 7 1 0 vigorous treatment with sodium ethoxide which raises a question as to the mechanism by which X is formed in the reaction. R-q 3 --NR J Cl -N Because of the undesirable presence of X in the reacI CsH5 O tion product arid its possible origin in the conversion of CsHa R, R, RIX into X under the conditions of the reaction, another I I1 Me H C1 milder method was sought for the preparation of IX. I11 H OH C1 The selection of a better leaving group than sulfinate IV H H NO, n-as a possible improvement. The elimination of an anion such a? acetate from the appropriately substituted hydroxylamine Qeenied a likely prospect, since the prerequisite generation of an adj acerit carbanion would be @YS02C6H4Me @N / analogous to that occurring in the foregoing sulfinate I elimination. Xccordingly, the available 7-chloro-1,3,0 0 &5-t et rahydro-4-hydroxy-5-pheny1-2H-l,4benzodiazepin-%one (XI)6 11-as acetylatd to give the 4-acetoxy v VI compound XI1 n hich was treated it-ith triethL’H-l,4-beiizodiazepin-2-oiie (YIII) which was easily J laniine to bring about the elimination of acetate. :iccomplished from the readily available 1-11(Chart I ) . Triethylamine n as chosen over sodium ethoxide i n *Ilthough t h e activation of the 3-methylene group of order to decrease the possibility of ester cleavage. T.311 v-hich 1- adjacent to a lactam carbonyl group is From XII, both IX arid X n-ere again obtained in a less than that of Proctor’s ketone T‘, conditions similar ratio of b : 1. I t n as possible to isomerize IX into X
q5
-
c , q 3- q S
C,,H
SI
fCH,COrO
c1
CHARTI
5 clq< Clq xH5 1 \
H
‘OH
H
C6Hj ‘OCOCH;
2%
\
C,H, ‘so:C,H_CH,
C6Hj
H
VI1
XI1Et S
?, aOEt
EtJBH,
rcr;rj - q-) clq0
JeE..EL
2%
c1
-K
\aOEt EcS
01
c1
C,H
X
111
-----IiBr
H
c,H
CGH;
IX
SI11
IH.0.
1‘”
q-$+
c1
C6H5
H
XIV ( 2 ) G. R. Proctor, C h e m . I n d . (London), 408 (1960). (3) A. V. Robertson, J. E. Francis. and 8. WitkoD, J . A n . C h e m . Soc., 84, 1709 (1962). (4) A. H Jackson, G. W.Kenner, and W.G. Terry, Tetrahedron Letters, 9 2 1 (1962). ( 5 ) E. Segishi and A. R. Day, J . Org. Chem., 30, 43 (1965)
by heating with triethylamine, thus leaving unclear the course by which X arose in the reaction mixture. , 26, 4936 (1961). ( 7 ) S. C . Bell, T. S Sulkouski, C . Gochman, and S. J. Childress, %bid 27
( 6 ) L. H. Sternbach and E. Reeder, tbid
562 (1962).
