Supplementary Material (ESI) for Perkin Transactions

Supplementary Material (ESI) for Perkin Transactions

This journal is © The Royal Society of Chemistry 2001

Supplementary data

Preparations.

IR spectra were recorded using a Shimadzu 435 spectrometer, and NMR spectra were recorded on Perkin Elmer R24 or R32 instruments using TMS as internal standard and deuteriochloroform as solvent; UV-visible spectra were recorded on a Perkin Elmer Lambda 5; melting points were determined with a Kofler hot stage microscope and are uncorrected. Pentane was acid-washed, alkali-washed, dried (CaCl2), and fractionally distilled from phosphorus pentoxide. Ether means diethyl ether which was purified by passing through an alumina column. Arenesulfonyl chlorides were recrystallised (petrol) before use.

Oximes. The variously substituted benzaldehyde oximes were all prepared in good yields from the corresponding aldehydes and hydroxylammonium chloride by catalysis with sodium ethanoate in aqueous methanol in the usual way.6,8 All except the parent (which was distilled) were recrystallised from aqueous methanol.

3-Chlorobenzaldehyde oxime: m.p. 71-75 oC, lit.,18 72-72.5 oC; H: 9.3 (1H, br, ex. D2O), 8.0 (1H, s), 7.1-7.6 (4H, m).

4-Chlorobenzaldehyde oxime: m.p. 103-107 oC, lit.,18 107-109 oC; H: 8.7 (1H, ex. D2O), 8.15 (1H, s), 7.4 (4H, s).

4-Cyanobenzaldehyde oxime: m.p. 174-176 oC, lit.,19 143-145 oC; H: 8.1 (1H, s), 7.5 (4H, s), the exchangeable proton was not observed.

3-Methylbenzaldehyde oxime: m.p. 58-60 oC, lit.,20 60 oC; H: 9.2 (1H, br, ex. D2O), 8.1 (1H, s), 7.1-7.4 (4H, m), 2.3 (3H, s).

4-Methylbenzaldehyde oxime: m.p. 74-76 oC, lit.,18 76-78 oC; H: 8.1 (1H, s), 7.0-7.5 (4H, q), 2.3 (3H, s), the exchangeable proton was not observed.

4-Methoxybenzaldehyde oxime: m.p. 60-64 oC, lit.,21 65 oC (E-isomer); H: 8.1 (1H, s), 7.6-6.8 (4H, q), 3.8 (3H, s), the exchangeable proton was not observed.

4-(Dimethylamino)benzaldehyde oxime: m.p. 135-150 oC, lit.,18 144-145 oC; H: 8.1 (1H, s), 6.5-7.5 (4H, q), 2.9 (6H, s), the exchangeable proton was not observed.

N-Substituted hydroxylamines. All N-substituted hydroxylamines were made by reduction of the corresponding oximes using sodium cyanoborohydride in methanolic HCl (generated from ice-cold methanol and acetyl chloride) with methyl orange as indicator.6,8,10 All products were crystalline and purified by sublimation under reduced pressure.

N-3-Chlorobenzylhydroxylamine. 82%, m.p. 45-49 oC; H: 7.4-7.2 (4H, m), 6.6 (2H, br, ex. D2O), 3.89 (2H, s).

N-4-Chlorobenzylhydroxylamine. 97%, m.p. 79-83 oC, lit.,19 87-88.5 oC; H: 7.2 (4H, s), 6.1-5.7 (2H, br, ex. D2O), 3.9 (2H, s).

N-4-Cyanobenzylhydroxylamine. 75%, m.p. 120-122 oC, lit.,19 127-128.5 oC; H: 7.75-7.45 (4H, m), 5.25 (2H, br, ex. D2O), 4.05 (2H, s).

N-3-Methylbenzylhydroxylamine. 73%, m.p. 39-40 oC; H: 7.0 (4H, s), 5.85-5.50 (2H, br, ex. D2O), 3.85 (2H, s), 2.30 (3H, s).

N-4-Methylbenzylhydroxylamine. 51%, m.p. 59-61 oC; H: 7.05 (4H, s), 5.9 (2H, br, ex. D2O), 3.85 (2H, s), 2.75 (3H, s).

N-4-Methoxybenzylhydroxylamine. 94%; H: 7.20-6.65 (4H, q), 6.35 (2H, br, ex. D2O), 3.80 (2H, s), 3.67 (3H, s).

N-4-Dimethylaminobenzylhydroxylamine (for which thymol blue was used as indicator). 56%, m.p. 78-83 oC; H: 7.20-6.55 (4H, q), 6.47 (2H, br, ex. D2O), 3.82 (2H, s), 2.85 (6H, s).

N-Arylmethyl-N'-hydroxydiazene oxides (named as the tautomeric N-nitroso-N-arylmethylhydroxylamines). All were prepared in the same way from the substituted N-benzylhydroxylamines in ice-cold hydrochloric acid containing methylated spirit and ice-cold aqueous sodium nitrite.6,8 The precipitated product was filtered at the pump and dried under vacuum; further material was also obtained by ether extraction of the aqueous filtrate, and combined yields are quoted. Generally, compounds were not purified but used directly for the preparation of the azoxyoxysulfonylarene.

N-Nitroso-N-(3-chlorobenzyl)hydroxylamine. 36%, m.p. 42-46 oC; H: 9.4 (1H, br, ex. D2O), 7.15 (4H, s), 5.26 (2H, s).

N-Nitroso-N-(4-chlorobenzyl)hydroxylamine. 77%, m.p. 125-127 oC; H: 7.3 (4H, s), 5.15 (2H, s), the exchangeable proton was not observed.

N-Nitroso-N-(4-cyanobenzyl)hydroxylamine. 79%, m.p. 105-111 oC; H: 7.20 (4H, s), 5.15 (2H, s), the exchangeable proton was not observed.

N-Nitroso-N-(4-methoxybenzyl)hydroxylamine. 69%, m.p. 45-56 oC; H: 7.3-6.6 (4H, q), 5.05 (2H, s), 4.7 (1H, br, ex. D2O), 3.7 (3H, s).

N-Nitroso-N-(4-dimethylaminobenzyl)hydroxylamine. 93%; H: 7.4-6.6 (4H, q), 5.10 (2H, s), 2.95 (6H, s), the exchangeable proton was not observed.

N-Nitroso-N-(4-methybenzyl)hydroxylamine. 94%, m.p. 125-131 oC; H: 7.2 (4H, s), 6.6 (1H, br, ex. D2O), 5.15 (2H, s), 2.35 (3H, s).

N-Nitroso-N-(3-methybenzyl)hydroxylamine. 75%, oil isolated by ether extraction; H: 7.20 (4H, s), 5.15 (2H, s), 2.30 (3H, s), the exchangeable proton was not observed.

Substituted benzylazoxyoxysulfonylarene. (1): By the Tipson method.6,8,11

p-(3-Chlorobenzylazoxyoxysulfonyl)toluene (1f). 30%, m.p. 82-85 oC; H: 7.95-7.20 (4H, q), 7.25 (4H, s), 5.1 (2H, s), 2.46 (3H, s); C: 49.94, H: 3.93, N: 8.26; C14H13ClN2O4S requires C: 49.34, H: 3.84, N: 8.22.

p-(4-Chlorobenzylazoxyoxysulfonyl)toluene (1e). 48%, m.p. 111-112 oC; H: 7.90-7.10 (4H, q), 7.17 (4H, s), 5.07 (2H, s), 2.45 (3H, s); C: 49.37, H: 3.64, N: 8.19.

p-(4-Cyanobenzylazoxyoxysulfonyl)toluene (1m). 68%, m.p. 143-145 oC; H: 7.90-7.15 (8H, m), 5.15 (2H, s), 2.46 (3H, s); C: 54.48, H: 3.90, N: 12.66; C15H13N3O4S requires C: 54.37, H: 3.95, N: 12.68.

p-(3-Methylbenzylazoxyoxysulfonyl)toluene (1d). m.p. 87-88 oC; H: 7.85-6.95 (8H, m), 5.05 (2H, s), 2.4 (3H, s), 2.25 (3H, s).

p-(4-Methylbenzylazoxyoxysulfonyl)toluene (1c). 41%, m.p. 91-93 oC; H: 7.90-6.95 (4H, q), 7.02 (4H, s), 5.00 (2H, s), 2.41 (3H, s), 2.28 (3H, s).

p-(4-Methoxybenzylazoxyoxysulfonyl)toluene (1b). 97%, m.p. 63-65 oC; H: 7.90-7.25 (4H, q), 7.25-6.70 (4H, q), 5.05 (2H, s), 3.77 (3H, s), 2.43 (3H, s).

4-Methylbenzylazoxyoxysulfonyl(4-bromo)benzene (1h). 57%, m.p. 88-90 oC; H: 7.90-7.45 (4H, q), 7.07 (4H, s), 5.05 (2H, s), 2.33 (3H, s).

(2) Aqueous method.12 This method is described for one compound and used for four others.

4-Methylbenzylazoxyoxysulfonyl(4-methoxy)benzene (1g). An aqueous solution of sodium hydroxide (2.0 mol dm-3, 1.2 cm3, 2.4 mmol) was added drop-wise to an ice-cold stirred solution of N-nitroso-N-(4-methybenzyl)hydroxylamine (0.19 g, 1.14 mmol) and 4methoxybenzenesulfonyl chloride (0.59 g, 2.85 mmol) in acetone (5 cm3) over 15 min. When the precipitate appeared, more water (0.5 cm3) was added and the reaction was stirred at 0 oC for 30 min., then more water (2 cm3) was added and the product was filtered at the pump. It was dried under vacuum (0.39 g) then recrystallised at low temperatures from ether/pentane and triturated with ether (m.p. 86-87 oC; H: 7.95-6.85 (4H, q), 7.15 (4H, s), 5.10 (2H, s), 3.87 (3H, s), 2.34 (3H, s).

4-Methylbenzylazoxyoxysulfonyl(4-cyano)benzene (1i). 36%, m.p. 70-75 oC; H: 8.15-7.60 (4H, q), 7.15 (4H, s), 5.12 (2H, s), 2.41 (3H, s).

3-Chlorobenzylazoxyoxysulfonyl(4-methoxy)benzene (1j). 59%, m.p. 85-90 oC; H: 7.95-6.80 (4H, q), 7.25 (4H, m), 5.11 (2H, s), 3.88 (3H, s); C: 47.28, H: 3.75, N: 7.72; C14H13ClN2O5S requires C: 47.13, H: 3.67, N: 7.85.

3-Chlorobenzylazoxyoxysulfonyl(4-bromo)benzene (1k). 44%, m.p. 101-104 oC; H: 7.95-7.25 (8H, m), 5.1 (2H, s).

3-Chlorobenzylazoxyoxysulfonyl(4-cyano)benzene (1l). 58%, m.p. 102-106 oC; H: 8.80-7.20 (8H, m), 5.35 (2H, s).

References 1-17 are given in the main publication.

18.R. H. Wiley and B. J. Wakefield, J. Org. Chem., 1960, 25, 546.

19.M. Kawase and Y. Kikugawa, J. Chem. Soc., Perkin Trans 1, 1979, 643.

20.C. W. Shoppee, J. Chem. Soc., 1932, 696.

21.J. Smolíková, O. Exner, G. Barbaro, D Macciantelli, and A. Dondoni, J. Chem. Soc., Perkin Trans. 2, 1980, 1051.