5976 J . Org. Chem., Vol. 64, No. 16, 1999
Darbeau et al.
N-(4-Meth ylben zyl)a ceta m id e: mp 109-111 °C (lit.35b mp
110-111 °C); IR (CHCl3) 3310, 1660 cm-1; 1H NMR (CDCl3) δ
2.01 (s, 3H), 2.34 (s, 3H), 4.39 (d, 2H, J ) 5.6 Hz), 5.65 (bs,
1H), 7.05-7.20 (ABq, 4H); UV (Et2O) λmax ) 256 nm (ꢀ ) 95),
320 nm (ꢀ ) 16).
Ta ble 8. Rela tive Resp on se F a ctor s for th e Su bstitu ted
Dip h en ylm eth a n es ver su s th e Cor r esp on d in g P a r en t
Dip h en ylm eth a n ea
sample
ref
RRFb
2-methyldiphenylmethane
3-methyldiphenylmethane
4-methyldiphenylmethane
2-methoxydiphenylmethane
3-methoxydiphenylmethane
4-methoxydiphenylmethane
mixture of the isomeric
diphenylmethane
1.12
1.10
1.01
1.02
1.02
1.04
1.02
N-(4-Ch lor oben zyl)a ceta m id e: mp 106-108 °C (lit.35c mp
106-107 °C); IR (CHCl3) 3305, 1657, 1075 cm-1 1H NMR
;
(CDCl3) δ 2.03 (s, 3H), 4.40 (d, 2H, J ) 5.6 Hz), 5.78 (bs, 1H),
7.23-7.31 (ABq, 4H).
N-(4-Nitr oben zyl)a ceta m id e: mp 127-129 °C (lit.35d mp
130-131 °C); IR (CHCl3) 3305, 1655, 1250, 1050 cm-1; 1H NMR
(CDCl3) δ 2.01 (s, 3H), 2.34 (s, 3H), 4.39 (d, 2H, J ) 5.6 Hz),
5.65 (bs, 1H), 7.05-7.20 (ABq, 4H); UV (Et2O) λmax ) 293 nm
(ꢀ ) 486), 315 nm (ꢀ ) 27).
4-methyldiphenyl-
methane
4-(methylbenzyl)toluenesc
1.02
a
Determined by the method in ref 32. b Relative response factor.
N-Ben zylben za m id e: mp 103-104 °C (lit.35e 104-105 °C);
IR (Nujol) 3289, 1638, 1491 cm-1; 1H NMR (CDCl3) δ 4.65 (d,
2H, J ) 5.7 Hz), 6.55 (bs, 1H), 7.29-7.50 (m, 8H), 7.80 (d, 2H,
J ) 6.9 Hz).
c Determined for the mixture of isomers.
2-Meth oxy- a n d 4-Meth oxyd ip h en ylm eth a n es: Gen -
er a l m eth od . The appropriate hydroxydiphenylmethane (920
mg, 5.0 mmol) was added to a stirred solution of NaOH (210
mg, 5.25 mmol) in 5 mL of water at 25 °C with stirring.
Dimethyl sulfate (523 µL, 5.5 mmol) was then added with
stirring over the course of 1 h after which the suspension was
refluxed for 12 h. It was then cooled to 25 °C and was poured
into 25 mL of NaOH (pH ∼ 13) and extracted with ether. The
organic layer was washed with water and then dried over
MgSO4; solvent removal in vacuo afforded a golden yellow oil.
This crude product was distilled (bp 150-160 °C) at the oil
pump producing a colorless oil (600 mg, 3 mmol, 60%).
2-Meth oxyd ip h en ylm eth a n e: 1H NMR (CDCl3) δ 3.79 (s,
3H), 3.97 (s, 2H), 6.58-7.31 (m, 9H).
N-(4-Meth ylben zyl)ben za m id e: mp 133-134 °C (lit.35f
136-138 °C); IR (Nujol) 3290, 1640, 1380 cm-1 1H NMR
;
(CDCl3) δ 2.35 (s, 3H), 4.63 (d, 2H, J ) 5.7 Hz), 6.31 (bs, 1H),
7.05-7.27 (m, 3H), 7.30-7.56 (m, 2H), 7.82 (d, 2H, J ) 7.0
Hz).
N-Ben zyl-N-4-tolu en esu lfon a m id e. Following the proce-
dure of Holmes and Ingold,36 benzylamine (20 g, 0.19 mol) was
dissolved in pyridine (75 cm3, 0.93 mol) and p-toluenesulfonyl
chloride (40 g, 0.21 mol) was added with stirring over 30 min
at 25 °C. After complete addition, the warm, red solution was
stirred for a further 1 h; it was then poured into 150 cm3 of
water, and the white/yellow precipitate that formed was
filtered out and dried at oil pump vacuum. The solid was then
recrystallized from ethanol to yield (45%) yellow crystals: mp
111-113 °C (lit.36 mp 113-114 °C); IR (KBr) 3269, 1598, 1454,
1094, 1028 cm-1; 1H NMR (CDCl3) δ 2.43 (s, 3H), 4.11 (d, 2H,
J ) 7.1 Hz), 4.28 (bs, 1H), 7.17-7.31 (m, 7H), 7.74-7.77 (d,
2H, J ) 9.0 Hz).
4-Meth oxyd ip h en ylm eth a n e: 1H NMR (CDCl3) δ 3.78 (s,
3H), 3.92 (s, 2H), 6.75-7.35 (m, 9H).
Rela tive Resp on se F a ctor An a lyses. Using the method
of Rosie and Grob,32 the relative response factors (RRFs) of
the individual methyldiphenylmethanes (MeDPMs) versus
diphenylmethane (DPM), of the isomeric 4-methylphenyl-
methyltoluenes versus 4-MeDPM, and of the individual meth-
oxydiphenylmethanes versus DPM were determined (Table 8).
Ester s. 4-Meth ylben zyl a ceta te, 4-ch lor oben zyl a ce-
ta te, 4-n itr oben zyl a ceta te, 4-m eth oxyben zyl a ceta te,
4-m eth ylben zyl ben zoa te, a n d ben zyl tosyla te were pre-
pared by decomposition of the corresponding N-nitrosoamides
in CDCl3. In each case the major (>98%) product was the
appropriate ester, but small amounts of the corresponding
amides (via denitrosation22a) were also formed. The nitrosobenz-
amides also yielded a small amount (<0.1%) of the hydrocar-
bon via decarboxylation. The 1H NMR spectra of the decom-
position products were compared with the spectral data for
the authentic esters from The Aldrich Library of NMR Spectra,
2nd ed., from The Properties of Organic Compounds, CRC
Press Database, CD-ROM, 1993, or from The Chemistry of
Organic Compounds, Chapman Hall Database, CD-ROM,
1982-1995.
N-Alk yl-N-n itr osoa m id es (1a -f): Gen er a l Meth od . Fol-
lowing the method of White et al.,15d an ice-cold suspension of
NaOAc (1.44 g, 15 mmol, 10 equiv) and N2O4 (l) (0.5 cm3, 8.1
mmol) was treated with a solution of the appropriate N-
alkylamide (1.5 mmol) in 2.5 cm3 CH2Cl2. After being stirred
for 1 h at 0 °C, the suspension was washed successively with
ice cold saturated solutions of NaCl, Na2CO3, and NaCl. The
organic phase was dried over Na2SO4 and the solvent removed
in vacuo. Yellow oils (1.5 mmol, 100%) were obtained.
N-Ben zyl-N-n itr osoa ceta m id e (1a ): IR (Nujol) 1725,
1
1605, 1502, 1372 cm-1; H NMR (CDCl3) δ 2.80 (s, 3H), 4.92
(s, 2H), 7.18-7.28 (m, 5H); UV (CH3CN) λmax ) 425 nm (ꢀ )
66), 405 nm (ꢀ ) 63), 394 nm (sh).
N-(4-Meth ylben zyl)-N-n itr osoa ceta m id e (1b): IR (Nujol)
1725, 1609, 1502, 1375 cm-1; 1H NMR (CDCl3) δ 2.29 (s, 3H),
2.78 (s, 3H), 4.88 (s, 2H), 7.08-7.10 (m, 4H).
N-(4-Ch lor oben zyl)-N-n itr osoa ceta m id e (1c): IR (Nujol)
1725, 1600, 1502, 1375 cm-1; 1H NMR (CDCl3) δ 2.80 (s, 3H),
4.88 (s, 2H), 7.14-7.25 (ABq, 4H); UV (Et2O) λmax ) 420 nm
(ꢀ ) 22), 405 nm (ꢀ ) 124), 392 nm (sh), 289 nm (ꢀ ) 312).
N-(4-Nitr oben zyl)-N-n itr osoa ceta m id e (1d ): IR (Nujol)
P r ep a r a tion s of Rea gen ts. N-Alk yla ceta m id es a n d
N-Alk ylben za m id es: Gen er a l Meth od . Following the pro-
cedure of Heyns and von Bebenburg34b the required benzyl-
amine (55 mmol) in 15 cm3 of ethyl ether was added dropwise
to acetic anhydride (17.4 cm3, 184 mmol, 3.3 equiv) with
stirring over 40 min at 25 °C. The initial cloudiness dissipated
after ∼20 min. The solution was washed, successively with
dilute H2SO4 (pH ∼3), NaHCO3, and water; it was then dried
over Na2SO4. Removal of ether in vacuo afforded a pale yellow
oil which solidified on cooling. Recrystallization from benzene-
hexane yielded (80-90%) of white needlelike crystals.
N-Ben zyla ceta m id e: mp 59-60 °C (lit.35a mp 59-60 °C);
1
1720, 1575, 1355 cm-1; H NMR (CDCl3) δ 2.85 (s, 3H), 5.01
(s, 2H), 7.24-8.22 (ABq, 4H).
N-Ben zyl-N-n itr osoben za m id e (1e): IR (Nujol) 1719,
1609, 1502, 1375 cm-1; 1H NMR (CDCl3) δ 5.14 (s, 2H), 7.36-
7.60 (m, 10H).
N-(4-Meth ylben zyl)-N-n itr osoben za m id e (1f): IR (Nu-
1
jol) 1720, 1610, 1510, 1375 cm-1; H NMR (CDCl3) δ 2.31 (s,
3H), 5.08 (s, 2H), 7.09-7.76 (m, 9H).
1
IR (Nujol) 3310, 1660 cm-1; H NMR (CDCl3) δ 1.98 (s, 3H),
N-Ben zyl-N-n itr oso-4-tolu en esu lfon a m id e (24): Follow-
ing the procedure of Overberger and Anselme,37 a solution of
N-benzyl-4-toluenesulfonamide (10.5 g, 40 mmol) in glacial
acetic acid (50 cm3) and acetic anhydride (200 cm3) at 0 °C
was treated with powdered sodium nitrite (60 g, 85 mmol) over
the course of 3 h. The resultant green mixture was stirred at
4.38 (d, 2H, J ) 5.5 Hz), 5.90 (bs, 1H), 7.18-7.38 (m, 5H); UV
(Et2O) λmax ) 256 nm (ꢀ ) 97), 320 nm (ꢀ ) 16).
(34) (a) Nystrom, R. F.; Berger, C. R. A. J . Am. Chem. Soc. 1958,
80, 2896. (b) Heyns, K.; v. Bebenburg, W. Chem. Ber. 1953, 86, 278.
(35) (a) Beilstein; Vol. 12, 2nd Suppl., p 588. (b) Beilstein; Vol. 12,
3rd Suppl., p 2522. (c) Beilstein; Vol. 12, 3rd Suppl., p 2346. (d)
Beilstein; Vol. 12, 3rd Suppl., p 2369. (e) Beilstein; Vol. 12, 3rd Suppl.,
p 2259. (f) Beilstein; Vol. 12, 4th Suppl., p 2577.
(36) Holmes, E. L.; Ingold, C. K. J . Chem. Soc. 1925, 127, 1800.
(37) Overberger, C. G.; Anselme, J . J . Org. Chem. 1963, 28, 592.