1420 J . Org. Chem., Vol. 61, No. 4, 1996
Mella et al.
TCB and adamantanecarboxylic acid (1d ) (0.05 M, 360 mg, 2
mmol) for 2 h, followed by general workup and silica gel
chromatography (cyclohexane-EtOAc and then EtOAc-
MeOH), gave 60 mg of 5-(1-adamantyl)benzene-1,2,4-tricar-
bonitrile (2a ) (75%) and 20 mg of 3-(2,4,5-tricyanophenyl)-
adamantanecarboxylic acid (2d ) (20%, dec >270 °C,
nitroethane).
adamantyl)-1,2,4-benzenetricarbonitrile (2a ) (28%) and 23 mg
of [1-[3-(2,4,5-tricyanophenyl)adamantyl]]methanol (2g) (64%,
mp 220-222 °C, cyclohexane-benzene).
2g: 1H NMR (in CDCl3) δ 1.4 (exch; OH), 1.6 (bs, 4H), 1.8
(m, 2H), 1.95 (bs, 2H), 2.05-2.2 (m, 4H), 2.3 (bs, 2H), 3.35 (s,
2H), 7.9 and 8.05 (s, 2H); 13C NMR 28.30 (2 CH), 35.31 (CH2),
35.57 (2 CH2), 38.98, 39.99 (2 CH2), 42.08 (CH2), 72.48 (OCH2),
113.48, 113.94, 114.32 (CN), 115.80 (CN), 116.54 (CN), 119.29,
132.13 (CH), 139.39 (CH), 158.9. Anal. Calcd for C20H19N3O:
C, 75.68; H, 6.03; N, 13.24. Found: C, 75.18; H, 6.21; N, 13.18.
P h otoch em ica l Rea ction in th e P r esen ce of CAN a n d
Ad a m a n ta n e (1a ). A solution containing 800 mg of cerium-
(IV) ammonium nitrate (CAN) (0.04 M, 1.6 mmol) and 108 mg
(0.02 M, 0.8 mmol) of adamantane (1a ) in 40 mL of MeCN
subdivided in two quartz tubes was flushed with argon for 15
min and then irradiated with a multilamp reactor fitted with
six 15-W phosphor-coated lamps (maximum of emission, 320
nm). After 2 h the orange color had disappeared and a white
precipitate had formed. The solvent was evaporated and the
residue treated with water and CH2Cl2. The organic layer was
dried and concentrated. The conversion of adamantane was
determined by GC analysis while the 1H and 13C NMR spectra
of the organic residue were diagnostic for the identification of
the type of products primarily formed during the irradiation
(nitrates or alcohols or acetamides) and their relative ratios.
In this case two main products were present in the crude
mixture, both arising from the attack at the tertiary position:
1-adamantyl nitrate (characteristic was the quaternary carbon
at 86.30 ppm) and 1-adamantylacetamide (characteristic were
the quaternary carbons at 50.64 and 169.37 ppm and the
methyl carbon at 24.56 ppm, compared with an authentic
sample). The corresponding 2-adamantyl derivatives were
present in smaller quantities (characteristic for 2-adamanty-
lacetamide were the methyl carbon at 24.42 ppm and the
methine carbon at 52.89 ppm and for 2-adamantyl nitrate the
quaternary carbon at 86.23 ppm). The ratio between tertiary
vs secondary position attack was 14:1 (as confirmed also by
GC analysis). The mixture was then chromatographed on a
silica gel column eluting with cyclohexane-EtOAc mixtures
of increasing polarity, all containing 0.1% triethylamine to
minimize the possible hydrolysis of nitrates owing to silica gel
acidity. Despite this precaution, 1-adamantanol (11a ) (30 mg)
(30%) and N-(1-adamantyl)acetamide (8a ) (60 mg, 53%) were
isolated as main products (both identified by comparison). A
spectroscopic characterization of 1-adamantyl nitrate (10a )
was possible, since the carbon-13 signals were separated from
those of adamantane and N-(1-adamantyl)acetamide, both
reported in the literature.22
2d : 1H NMR (in CD3OD) δ 1.7-2.0 (m, 8H), 2.2 (bs, 4H),
2.25 (bs, 2H), 7.93 and 8.1 (s, 2H); 13C NMR δ 29.33 (2CH),
34.68 (CH2), 37.75 (2CH2), 38.87, 39.37 (2CH2), 41.64, 41.82
(CH2), 113.44, 113.72, 114.25 (CN), 115.53 (CN), 116.42 (CN),
119.12, 132.24 (CH), 139.44 (CH), 158.70, 183.17 (COOH).
Anal. Calcd for C20H17N3O2: C, 72.49; H, 5.17; N, 12.68.
Found: C, 72.08; H, 5.01; N, 12.28.
P h otoch em ica l Rea ction betw een TCB a n d 1-Meth -
oxya d a m a n ta n e (1e). Irradiation of a solution of TCB and
1-methoxyadamantane (1e) (0.03 M, 200 mg, 1.2 mmol) for
10 h, followed by general workup, gave, after silica gel
chromatography (cyclohexane-EtOAc), 20 mg of (2,4,5-tricy-
anophenyl)methyl adamantyl ether (4) (62%, oil) and 10 mg
of (2,3,5,6-tetracyanophenyl)methyl adamantyl ether (5) (23%,
oil).
4: 1H NMR (in CDCl3) δ 1.6-1.75 (m, 6H), 1.9 (bs, 6H), 2.25
(bs, 3H), 4.75 (s, 2H, H-1), 8.05 and 8.24 (s, 2H); 13C NMR δ
30.4 (3CH), 36.06 (3CH2), 41.27 (3CH2), 59.06 (OCH2), 74.55,
113.58, 113.66, 114.18 (CN), 114.87 (CN), 115.00 (CN), 119.36,
132.97 (CH), 136.17 (CH), 150.41. Anal. Calcd for
C20H19N3O: C, 75.68; H, 6.03; N, 13.24. Found: C, 76.05; H,
6.15; N, 13.05.
5: 1H NMR (in CDCl3) δ 1.6-1.75 (m, 6H), 1.9 (bs, 6H), 2.25
(bs, 3H), 4.85 (s, 2H, H-1), 8.12 (s, 1H); 13C NMR δ 30.49 (3CH),
36.03 (3CH2), 40.61 (3CH2), 59.30 (OCH2), 75.67, 111.67,
112.59, 120.67 (CN), 121.45 (CN), 135.66 (CH), 149.21. Anal.
Calcd for C21H18N4O: C, 73.66; H, 5.30; N, 16.36. Found: C,
73.95; H, 5.45; N, 16.15.
P h otoch em ica l Rea ction betw een TCB a n d 1-Ad a -
m a n tylm eth yl Meth yl Eth er (1f). Irradiation of a solution
of TCB and ether 1f (0.03 M, 216 mg, 1.2 mmol), for 6 h, gave,
after general workup and silica gel chromatography (cyclo-
hexane/EtOAc), 25 mg of [1-[3-(2,4,5-tricyanophenyl)adaman-
tyl]]methyl methyl ether (2f) (68%, mp 188-190 °C, benzene-
petroleum ether), 5 mg of 5-(1-adamantyl)benzene-1,2,4-
tricarbonitrile (2a ) (15%), and 3 mg of a two-product mixture
arising from deprotonation from the methyl (6) (3%) and
methylene groups (7) (5%) of the ether function. The small
quantity of these two last compounds did not allowed a further
purification but only a spectroscopic characterization. In the
proton spectrum the aliphatic parts of 6 and 7 were superim-
posed while the corresponding 13C signals were separated. The
elemental analysis of this mixture was in accordance with the
structures proposed.
10a : 13C NMR (in CDCl3) δ 30.84 (3CH), 35.69 (3CH2), 39.55
(3CH2), 89.88 (CONO2).
P h otoch em ica l Rea ction in th e P r esen ce of CAN a n d
ter t-Bu tyla d a m a n ta n e (1b). A solution containing cerium-
(IV) ammonium nitrate (CAN) and 153 mg (0.02 M, 0.8 mmol)
of tert-butyladamantane (1b) was irradiated for 4 h. After
general workup as above, the raw photolysate was separated
on a silica gel column (cyclohexane/EtOAc). Two main prod-
ucts were isolated in this case: N-[1-(3-tert-butyladamantyl)]-
acetamide (8b) (108 mg, 54%, mp 138-140 °C, cyclohexane)
and 3-tert-butyladamantanol (11b) (46 mg, 29%, mp 118-120
°C, cyclohexane), which was formed from the hydrolysis of the
corresponding nitrate. The structures of these compounds
were attributed on the basis of NMR and IR spectroscopic data.
8b:
2f: 1H NMR (in CDCl3) δ 1.5-1.65 (m, 4H), 1.65-1.85 (m,
2H), 1-9-2.2 (m, 4H), 2.2 - 2.4 (6H), 3.1 (s, 2H, OCH2), 3.4 (s,
3H, OCH3), 7.9 and 8.05 (s, 2H); 13C NMR δ 28.42 (2CH), 35.13,
35.41 (CH), 36.11 (2CH2), 39.08, 40.02 (2CH2), 42.72 (CH2),
59.42 (OCH3), 82.91 (OCH2), 113.6, 113.95, 114.46 (CN), 115.93
(CN), 116.65 (CN), 119.32, 132.26 (CH), 139.47 (CH), 159.16.
Anal. Calcd for C21H21N3O: C, 76.10; H, 6.39; N, 12.68.
Found: C, 75.85; H, 6.50 ; N, 12.30.
6: 1H NMR (in CDCl3) δ 1.4-2.3 (m, aliphatic protons
superimposed to those of 7), 3.18 (s, 2H, OCH2), 3.3 (s, 2H,
OCH2), 8.03 and 8.1 (s, 2H); 13C NMR δ 27.93 (3CH), 36.92
(3CH2), 38.76, 39.51 (3CH2), 69.38 (OCH2), 89.07 (OCH2),
113.53, 113.78, 114.4 (CN), 115.21 (CN), 116.59 (CN), 119.47,
132.46 (CH), 136.43 (CH), 150.15. 7: 1H NMR (in CDCl3) δ
1.4-2.3 (m, aliphatic protons superimposed to those of 6), 3.2
(s, 3H, OCH3), 4.75 (s, 1H), 7.95 and 8.05 (s, 2H); 13C NMR δ
27.98 (3CH), 36.47 (3CH2), 37.73 (3CH2), 39.13, 58.51 (OCH3),
89.07 (OCH), 113.5, 113.78, 114.21 (CN), 115.77 (CN), 116.57
(CN), 119.47, 134.02 (CH), 136.33 (CH), 157.5. Anal. Calcd
for C21H21N3O: C, 76.11; H, 6.39; N, 12.68. Found: C, 76.21;
H, 6.25; N, 12.48.
1H NMR (in CDCl3) δ 1.3 (s, 9H), 1.4-1.6 (m, 6H), 1.7
(bs, 2H), 1.8- 2.0 (m, 4H), 1.9 (s, 3H, NCOCH3), 2.15 (bs, 2H),
5.15 (exch, NH); 13C NMR δ 24.69 (CH3), 29.51 (2CH), 34.68,
35.07 (2CH2), 35.77 (CH2), 38.85, 40.65 (CH2), 41.00 (2CH2),
52.94, 169.07 (NCdO); IR cm-11660, 3200. Anal. Calcd for
C16H27NO: C, 77.06; H, 10.91; N, 5.62. Found: C, 76.85; H,
11.05; N, 5.45.
11b: 1H NMR (in CDCl3) δ 1.3 (s, 9H), 1.45-1.55 (m, 6H),
1.6-1.9 (m, 6H), 1.7 (exch, OH), 2.2 (bs, 2H); 13C NMR δ 24.72
P h otoch em ica l Rea ction betw een TCB a n d 1-Ad a -
m a n tylm eth a n ol (1g). From the irradiation of a solution of
TCB and the alcohol 1g (0.03 M, 200 mg, 1.2 mmol) for 8 h,
and after general workup as above, were isolated 10 mg of 5-(1-
(22) Pouchert, C. J .; Behnke J . The Aldrich Library of 13C and 1H
FT NMR Spectra; Aldrich, 1993.
(23) Mella, M.; d’Alessandro, N. ; Freccero, M.; Albini, A. J . Chem.
Soc., Perkin Trans. 2 1993, 515.