[37477-17-1]  · C10H13NO2  · O-Mesitoylhydroxylamine  · (MW 179.24)

(reagent for electrophilic aminations, H2N transfers to nucleophiles)

Physical Data: oil; mp of N-acetyl-O-mesitoylhydroxylamine 128-129 °C.1

Preparative Method: a solution of 10.0 g (35.8 mmol) t-butyl N-mesitoyloxycarbamate in 150 mL of nitromethane was treated with a stream of anhydrous hydrogen chloride for 5-7 min. After standing for 15 min the precipitated solid (1) (mp 125-127 °C, dec) was filtered, washed with nitromethane, dried in air and then suspended in 100 mL of water and treated with 1 M sodium bicarbonate solution until gas evolution stopped. The resulting oil was extracted with three 15 mL portions of CH2Cl2, the extracts dried over magnesium sulfate, and the solvent removed from a water bath at room temperature under reduced pressure (ca. 12-20 mmHg). O-mesitoylhydroxylamine (2) remained as a clear, colorless oil; 5.5 g (86%) (eq 1).2

Handling, Storage, and Precautions: explosions which have been reported for compounds similar to (2), e.g. O-(Mesitylsulfonyl)hydroxylamine or O-(p-tolylsulfonyl)hydroxylamine,2 have not been described for (2).

Reactions with Amines.

While O-(mesitylsulfonyl)hydroxylamine is the reagent of choice for the N-amination of heteroaromatic and tertiary amines,1 it is (2) which should be used for the preparation of 1,1-disubstituted hydrazines from secondary amines (Table 1).1,2a,3 Compound (2) is also a good reagent for the amination of anionic nitrogen atoms of amides, pyrroles, and related compounds, as shown in Table 2.4,5

One should mention here that O-(2,4-dinitrophenyl)hydroxylamine (8) also aminates substrates of this type quite well.1,6,7 In contrast, O-(mesitylsulfonyl)hydroxylamine1 is not a good reagent for such reactions.

Miscellaneous Reactions.

O-Mesitoylhydroxylamine (2) was used (among others) for the a-amination of dilithiated carboxylic acids, RCHLiCO2Li;8 however, success was very poor. Other aminating reagents for these and other carbanions turned out to be much better, as excellently described in a recent review.9

Makhova et al. used (2) for the preparation of diaziridines,10 a reaction which is also performed with O-(mesitylsulfonyl)hydroxylamine.

Finally, (2) has been identified as an oxidative inhibitor of cysteine proteinases.11

Related Reagents.

O-(Diphenylphosphinyl)hydroxylamine; O-(Mesitylsulfonyl)hydroxylamine.

1. Tamura, Y.; Minamikawa, J.; Ikeda, M. S 1977, 1.
2. (a) Carpino, L. A. JACS 1960, 82, 3133. (b) Marmer, W. N.; Maerker, G. JOC 1972, 37, 3520.
3. Carpino, L. A. JACS 1963, 85, 2144.
4. Carpino, L. A. JOC 1965, 30, 321.
5. Carpino, L. A. JOC 1965, 30, 736.
6. Sheradsky, T. JHC 1967, 4, 413.
7. Sheradsky, T. TL 1968, 1909.
8. (a) Yamada, S.; Oguri, T.; Shioiri, T. CC 1972, 623. (b) Oguri, T.; Shioiri, T.; Yamada, S. CPB 1975, 23, 167.
9. Erdik, E.; Ay, M. CRV 1989, 89, 1947.
10. (a) Makhova, N. N.; Petukhova, V. Yu.; Khmel'nitskii, L. I. IZV 1982, 2107; BAU 1982, 1858. (b) Makhova, N. N.; Petukhova, V. Yu.; Khmel'nitskii, L. I. IZV 1982, 2331; BAU 1982, 2052.
11. Robinson, V. J.; Coles, P. J.; Smith, R. A.; Krantz, A. JACS 1991, 113, 7760.

Gernot Boche

Philipps-Universität Marburg, Germany

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