3874
M. Barbasiewicz et al. / Tetrahedron Letters 47 (2006) 3871–3874
usual work-up, the product was isolated by vacuum
19. Typical procedure for the synthesis of 1-cyano-1-phenyl-
cyclobutane (4a). A mixture of solid KOH (22.4 g,
0.4 mol), water (7.5 g), phenylacetonitrile (5.86 g,
0.05 mol), 1,3-dibromopropane (10.1 g, 0.05 mol), TBAB
(0.16 g, 0.5 mmol) and toluene (135 mL) was heated to
ꢀ100 °C with only occasional slow stirring to facilitate
liquification of the inorganic phase. Heating was removed
and the mixture was vigorously stirred (see Ref. 21). A
water bath was used at the beginning to avoid overboiling
(CAUTION! exothermic effect, reaction vessel should be
at least double the volume as compared to the reactants).
Then the mixture was refluxed with continuous vigorous
stirring for 1 h. After work-up the product was isolated by
vacuum distillation at 83–85 °C/0.3 Torr (lit.2f 107 °C/
8 Torr) to give 1-cyano-1-phenylcyclobutane (4.80 g, 61%)
as a colorless liquid. Physicochemical data of products 4c–e
were consistent with the literature. For characterization
data of compounds 4b and 4f see Ref. 22.
distillation (see Table 1). Physicochemical data of products
2a–d were consistent with the literature.
14. Typical procedure for the synthesis of 1-cyano-1-phenyl-
cyclopropane (3). To a mixture of solid KOH (9.54 g,
0.12 mol), 60% aqueous KOH (16.8 g, 0.18 mol), phenyl-
acetonitrile (5.86 g, 0.05 mol) and TBAB (0.16 g,
0.5 mmol), 1-bromo-2-chloroethane (14.3 g, 0.1 mol) was
added dropwise. A strong exothermic effect was observed
and the temperature was kept at 50 °C (external cooling).
After the additionstirringwas continuedat thistemperature
for 30 min. After usual work-up the product was isolated by
vacuum distillation at 72–74 °C/0.35 Torr (lit.20 65–74 °C/
0.4 Torr) to give 1-cyano-1-phenylcyclopropane (6.44 g,
90%) as a colorless liquid.
15. See, for example: (a) Nakagaki, R.; Sakuragi, H.; Mutai,
K. J. Phys. Org. Chem. 1989, 2, 187; (b) Mandolini, L.
Adv. Phys. Org. Chem. 1986, 22, 1; (c) Winnik, M. A.
Chem. Rev. 1981, 81, 491.
20. Kuntzel, H.; Wolf, H.; Schaffner, H. Helv. Chim. Acta.
¨
16. The products of allylation and diallylation of arylaceto-
nitriles may be formed in two possible ways: (1)
b-elimination of 1,3-dibromopropane and subsequent
allylation of carbanions with allyl bromide, or (2)
b-elimination of intermediate 1-aryl-1-cyano-4-bromo-
butane and its derivatives. Independent of which of these
ways is in fact realized, we observed that the amounts of
these products decreased with C–H acidity of arylaceto-
nitrile, giving support to the hypothesis that b-elimination
is dependent on the carbanion, the basicity of which
correlates well with the amount of elimination products:
1971, 54, 868–897.
21. Vigorous mechanical stirring of mixtures is crucial to
reproduce all of the presented results (especially yields
and amounts of by-products in the syntheses of
cyclobutanes).
22. Characterization data for new compounds: Compound 4b:
Oil, bp = 156–159 °C/1.4 Torr. 1H NMR (CDCl3,
200 MHz): d 6.82–6.98 (m, 3H), 3.90 (s, 3H), 3.88 (s,
3H), 2.70–2.88 (m, 2H), 2.27–2.69 (m, 3H), 1.94–2.14 (m,
1H). 13C NMR (CDCl3, 50 MHz): d 149.2, 148.6, 132.2,
124.5, 117.7, 111.1, 108.9, 55.9 (overlapped), 39.9, 34.7,
16.9. MS (EI, relative intensity) m/z = 217 (M+, 26), 202
(4), 189 (100), 186 (23), 174 (31), 119 (33). IR (neat): 2953,
2837, 2228, 1591, 1519, 1465, 1413, 1258, 1172, 1142, 1027,
809, 765, 643, 622 cmÀ1. Anal. Calcd for C13H15NO2: C
71.87, H 6.96, N 6.45. Found C 71.59, H 7.07, N 6.35.
Compound 4f: Oil, bp = 148–150 °C/20 Torr. 1H NMR
(CDCl3, 200 MHz): d 7.29–7.46 (m, 2H), 7.00–7.15 (m,
´
Fedorynski, M.; Marciniak, K., unpublished results.
17. We observed the gradual dependence of the boiling
(reflux) temperature of reaction mixtures as a function of
concentration of base in both of the series investigated
(from 103 °C for 55% KOH to 111 °C for 75% KOH, at
the beginning of reaction). One may assume that this effect
is related to the amount of water ‘accessible’ in this system
and the boiling points of ‘effective azeotropic mixtures’
above the liquids.
2H), 2.70–2.92 (m, 2H), 2.30–2.69 (m, 3H), 1.96–2.20 (m,
1H). 13C NMR (CDCl3, 50 MHz): d 162.1 (d, JC–F
=
1
3
18. For a similar interpretation see: (a) Landini, D.; Maia,
A. M.; Montanari, F. J. Chem. Soc., Chem. Commun.
1975, 950–951; (b) Landini, D.; Maia, A. M.; Montanari,
F. J. Am. Chem. Soc. 1978, 100, 2796–2801; (c) Landini,
D.; Maia, A. M.; Rampoldi, A. Gazz. Chim. Ital. 1989,
119, 513–517.
246 Hz), 135.6, 127.3 (d, JC–F = 8.4 Hz), 124.1, 115.7 (d,
2JC–F = 22 Hz), 39.6, 34.7, 17.0. MS (EI, relative intensity)
m/z = 175 (M+, 8), 160 (1), 147 (100), 133 (5), 120 (15). IR
(neat): 2998, 2954, 2231, 1602, 1511, 1233, 1163, 1102,
1014, 833, 596, 549, 622 cmÀ1. Anal. Calcd for C11H10NF:
C 75.41, H 5.75, N 7.99. Found C 75.52, H 5.71, N 8.05.