166/[440]
A. A. Volod’kin et al.
1120. Found (%): C, 67.84; H, 8.85; N, 4.16. C19H29NO4. Calculated (%): C, 68.03; H,
8.72; N, 4.18.
Monoethyl N-acetylamino(3,5-di-tert-butyl-4-hydroxybenzyl)malonate (2c). A
mixture of compound 1 (43.6 g, 0.1 mol) and AcONa (8.2 g, 0.1 mol) in water (30 mL)
and propan-2-ol (200 mL) was stored for 3 days at room temperature, after which 10%
HCl (35◦mL) was added. Compound 2c was obtained in a yield of 26.1 g (64%), m.p.
1
´
175–176 (from toluene). H NMR (DMSO-d6), δ: 1.24 (t, 3 I, CH2CH3, J = 7.1 Hz);
1.34 (s, 18 H, But); 1.89 (s, 3 H, COCH3); 3.22 (s, 2 H, CH2); 4.13 (2 H, CH3CH2, J =
7.1 Hz); 6.34 (s, 1 H, OH); 6.76 (s, 2 H, Ar); 7.39 (s, 1 H, NH). IR, ν/cm−1: 3633 (OH);
3345 (NHCOOCH3); 2954 (CH); 1749 (COOC2H5); 1714 (COOH); 1619 (HNCOCH3);
1533 (C C); 1435, 1235, 1212, 1149. Found (%): C, 64.89; H, 8.33; N, 3.31. C22H33NO6.
Calculated (%): C, 64.85; H, 8.16; N, 3.44.
Ethyl 2-N-acetylamino(3,5-di-tert-butyl-4-hydroxyphenyl)propanoate (3c) is
formed on heating monoethyl ester 2c to temperatures higher than 176◦C due to decarboxy-
1
lation. M.p. 135–136◦C (from toluene). H NMR (acetone-d6), δ: 1.68 (t, 3 H, CH3CH2,
J = 7.1 Hz); 1.42 (s, 18 H, But); 1.91 (s, 3 H, COCH3); 2.02 (dd, 1 Ha`, J = 6.2 Hz); 3.11
´
(dd, 1 Hb, J = 6.3 Hz); 4.09 (2 I, CH3CH2, J = 7.1 Hz); 4.60–4.64 (m, 1 Hn˜ ); 5.98 (s, 1 H,
OH); 6.95 (s, 2 H, Ar); 7.34 (d, 1 H, NH, J = 7.15 Hz). IR, ν/cm−1: 3354 (NHCOCH3);
3189 br. (OH); 2948 (CH); 1732 (COOC2H5); 1647 (HNCO); 1548 (C C); 1435; 1253;
1211; 1039. Found (%): C, 69.59; H, 9.13; N, 3.94; C21H33NO4. Calculated (%): C, 69.40;
H, 9.15; N, 3.85.
N-Acetylamino(3,5-di-tert-butyl-4-hydroxybenzyl)malonate (2d). A solution of
compound 2a (4.2 g, 0.01 mol) in water (50 mL) was added by 10% HCl (5 mL). The
precipitate formed was separated, dried at 25–30◦C, and crystallized from a toluene—EtOH
(9:1, vol.) mixture. The yield was 92–96%, m.p. 198–200◦C (from toluene). According to
1
the literature data [1] m.p. 148◦C. H NMR (DMSO-d6), δ: 1.34 (s, 18 H, But); 1.87 (s,
3 H, COCH3); 3.22 (s, 2 H, CH2); 6.74 (s, 2 H, Ar); 7.69 (s, 1 H, NH). IR, ν/cm−1: 3637
(OH); 3338 (NHCOCH3); 2954, 2913, 2872 (CH), 1716 (COOH); 1623 (HNCOCH3);
1536 (C C), 1435, 1214, 1155, 1121. Found (%): C, 63.24; H, 7.95; N, 3.86. C20H29NO6.
Calculated (%): C, 63.31; H, 7.70; N, 3.69.
N-Acetylamino(3,5-di-tert-butyl-4-hydroxybenzyl)malonic acid diammonium salt
(2e). Ammonia (2.2 mL, 0.1 mol) was added to a solution of acid 2d (3.37 g, 0.01 mol)
in EtOH (15 mL). The reaction mixture was stirred for 30 min, and ammonia and solvent
excess were distilled off. Water (10 mL) was added to the residue, and the mixture was
heated and filtered. The filtrate was cooled to 5–6◦C and stored until precipitation, and
the precipitate was separated by filtration. Compound 2e was obtained in a yield of 3.1 g
(83%), m.p. 177–178◦C (from EtOH). 1H NMR (DMSO-d6), δ: 1.29 (s, 18 H, But); 1.75 (s,
3 H, COCH3); 2.52 (s, 2 H, CH2); 3.85–4.01 (br.s,. 8 H, NH4); 6.80 (s, 2 H, Ar); 7.04–7.06
(br.s, 1 H, NH). Found (%): C, 57.95; H, 8.71; N, 10.26. C20H35N3O6. Calculated (%): C,
58.01; H, 8.53; N, 10.16.
N-Acetylamino(3,5-di-tert-butyl-4-hydroxybenzyl)malonic acid monopotassium
salt (4) was synthesized similarly to 2a in 56% yield, m.p. 250–252◦C (with de-
1
comp.). H NMR (DMSO-d6), δ: 1.27 (s, 18 H, But); 1.80 (s, 3 H, COCH3); 2.48
(s, 2 H, CH2); 3.41–3.46 (br.s, 3 H,HOH); 6.42–6.47 (br.s, 1 H, OH); 6.79 (s, 2 H,
Ar); 7.22–7.26 (br.s, 1 H, NH). IR, ν/cm−1: 3644 (OH); 3550–3100 br. (HOH); 3323
(NHCOCH3); 1550–1620 br. (HNCO, COO–, C C). Found (%): C, 54.04; H, 7.03; N,
ˆ
3.15; E, 8.60. C20H22KNO6 · 1.5H2O. Calculated (%): C, 54.32; H, 7.21; N, 3.06; K.
8.75.