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G. Kaupp et al. / Tetrahedron 56 (2000) 6899±6911
1
128.7, 128.9, 134.6, 136.3, 160.9. 3a: H NMR (CDCl3) d
1.32 (t, 3H), 3.71 (q, 2H), 7.38±7.69 (AA0BB0, 4H), 8.24 (s,
1H); 13C NMR (CDCl3) d 16.17, 55.77, 128.8, 129.2, 134.8,
and became very slow, due to aggregation of the 40 mm
grains into 0.5±3 mm particles.
1
136.4, 159.0. 3c: H NMR (CDCl3) d 1.31 (t, 3H), 2.97 (s,
6H), 3.58 (q, 2H), 6.63±7.63 (AA0BB0, 4H), 8.14 (s, 1H);
The material was ground in a large mortar and afterwards
reacted with ethylamine gas at 508C for a quantitative yield.
Clearly in technical runs large scale milling at suitable
cooling should be performed.
13C NMR (CDCl3) d 16.46, 40.04, 55.54, 111.51, 124.43,
129.23, 151.81, 160.25. 3d: H NMR (CDCl3) d 1.31 (t,
1
3H), 3.59 (q, 2H), 3.85 (s, 3H), 5.19 (s, 2H), 6.89 (m,
1H), 7.19±7.41 (m, 4H), 7.46±7.51 (m, 3H), 8.19 (s, 1H);
13C NMR (CDCl3) d 16.20, 55.40, 55.73, 70.65, 110.88,
111.23, 122.81, 127.32, 127.67, 128.28, 128.58, 128.98,
129.37, 136.67, 148.37, 151.63, 159.65; HRMS (CI,
i-C4H10) m/z found 270.1386 calcd for C17H19NO2
270.1375 (M1H)1
N-(4-Tolyl)-phthalimid 11. 296 mg (2.00 mmol) phthalic
anhydride and 214 mg (2.00 mmol) 4-toluidine were ball-
milled for 1 h and the product dried at 0.01 bar and 808C, to
give 507 mg (.99%) of product 11 mp 2048C; lit. 201±
2038C;38 IR (KBr) cm21 3461, 1715, 1514, 1465, 1383;
1H NMR (CDCl3) d 2.41 (s, 3H), 7.32 (s, 4H), 7.76
(m, 2H), 7.92 (m, 2H); 13C NMR (CDCl3) d 21.14,
123.62(2C), 126.41(2C), 129.00, 129.72(2C), 131.82,
134.25(2C), 138.10, 167.35
(R)-Thiazolidine-4-carboxylic acid 5. 242 mg (2.00
mmol) (l)-cysteine (4) and 62 mg (97%; 2.00 mmol) para-
formaldehyde were ball-milled at room temperature for 1 h.
After drying at 0.01 bar at 808C, 263 mg (100%) of 5 were
obtained; mp 1968C, lit. 196±1978C;37 IR (KBr) cm21 3052,
2942, 2346, 1630, 1557, 1463, 1386; 1H NMR (D2O) d 3.32
(mAB, 2H), 4.28 (m, 1H) 4.39 (m, 2H); 13C NMR (D2O) d
33.32, 48.98, 64.31, 172.22.
Cyclic imides 12/13 and amines. Crystals of succinimide
or glutarimide (200 mg, 2.02 or 1.77 mmol) were treated
with 1 bar or 0.8 bar of methyl- or dimethyl- or ethylamine
at RT or 808C in a previously evacuated 500 mL ¯ask and
left overnight or for 8 h. Excess gas was recovered in a 77 K
trap. The yield was quantitative in all cases.
Pyromellitic tetramethylamide 7. 436 mg (2.00 mmol)
pyromellitic dianhydride 6 were evacuated in a 100 mL
¯ask and treated overnight with 1 bar of gaseous methyl-
amine. Excess gas was condensed in a separate ¯ask at 77 K
and 610 mg (100%) of 7 collected: mp 3818C; IR (KBr)
N-Methyl-succinic diamide 14a. Mp 160.58C; lit. 159±
1
1618C;14a IR (KBr) cm21 1649, 1570; H NMR (D2O) d
2.40 (s, 3H), 2.62 (mc, 4H); 13C NMR (D2O) d 26.1, 30.7,
31.1, 175.4, 177.9.
1
cm21 3022, 1633, 1566, 1365; H NMR (D2O) d 2.46 (s,
12H), 7.38 (s, 2H); 13C NMR (D2O) d 24.78, 126.23,
138.12, 176.80.
N-Ethyl-succinic diamide 14b. Mp 1788C; lit. 176±
1
1788C;14b IR (KBr) cm21 1642, 1558; H NMR (D2O), d:
0.97 (t, 3H), 2.41 (mc, 4H), 3.15 (q, 2H); 13C NMR (D2O) d
14.0, 30.4, 30.8, 33.4, 171.3, 174.1.
Pyromellitic dimethylimide 8. 436 mg (2.00 mmol) of
crystalline 6 were exposed to 0.8 bar methylamine as
above and heated to 1608C overnight. Alternatively,
306 mg (1.00 mmol) 7 were heated to 1608C under vacuum
with occasional evaporation. 485 mg (100%) or 245 mg
(100%) of 8 were obtained. Alternatively, 306 mg 7 were
treated with 1 bar of HCl at RT in an evacuated 100 mL
¯ask over night, the excess gas condensed to a cooled
¯ask (77 K), and methylamine hydrochloride washed
away with water and the solid residue dried. The yield
was 243 mg (100%); mp 3818C; lit. 375±378;12 IR (KBr)
N, N0-Dimethyl-succinic diamide 14c. Mp 1898C; lit. 192±
1938C;39 the mp did not increase by recrystallization from
1
ethanol; IR (KBr) cm21 1695, 1630; H NMR (CDCl3) d
2.55 (m, 2H), 2.65 (m, 2H), 2.93 (s, 3H), 3.01 (s, 3H), 5.58
(bp, 1NH), 6.41 (bp, 1NH); 13C NMR (CDCl3) d 28.7, 30.7,
35.5, 37.0, 171.8, 175.1.
N-Methyl-glutaric diamide 15a. Mp 1288C; IR (KBr)
1
cm21 1645, 1548; H NMR (CDCl3/DMSO-d6) d 1.72 (m,
1
cm21 3037, 1702, 1578; H NMR (CDCl3) d 3.29 (s, 6H),
2H), 2.08 (m, 4H), 2.58 (d, 3H), 6.49 (bp, 1NH), 7.1
(bp, 1NH), 7.52 (bp, 1NH); 13C NMR (CDCl3/DMSO-d6)
d 21.3, 25.3, 34.5, 34.7, 172.4, 174.2; HRMS (CI, i-C4H10)
m/z found 144.0900 calcd for C6H13N2O 144.0899
(M1H)1.
8.26 (s, 2H); 13C NMR (CDCl3) d 24.49, 118.14, 137.35,
166.25.
Ethyl-tetrachlorophthalamic acid, ethylammonium salt
10. Technical 9 was recrystallized from CCl4. 572 mg
(2.00 mmol) of the anhydride was evacuated in a 100 mL
¯ask and left over night with 1 bar of ethylamine. Excess
gas was recovered and 750 mg (100%) product 10 collected;
mp 1908C; IR (KBr) cm21 3062, 1647, 1628, 1593; 1H NMR
(D2O) d 1.08 (t, 6H), 2.80 (q, 2H), 3.24 (q, 2H); MS (CI):
375±383 (M11 with correct isotope pattern for
C12H15Cl4N2O3). 500 g of 9 were evacuated in a 2 L round
bottomed ¯ask on a rotatory evaporator. The setup was
continuously ®lled with ethylamine (0.5±0.8 bar) from a
steel bottle by adjusting a needle valve while using a
security valve under a hood. The rotating ¯ask was
immersed in a cooling bath at about 148C. When the heat
production had ceased after 8 h the conversion was ca. 75%
N-Ethyl-glutaric diamide 15b. Mp 1338C; IR (KBr) cm21
1647, 1546; H NMR (CDCl3/DMSO-d6) d 1.01 (t, 3H),
1
1.62 (m, 2H), 2.03 (m, 4H), 3.07 (q, 2H), 6.47 (bp, 1NH),
7.1 (bp, 1NH), 7.51 (bp, 1NH); 13C NMR (CDCl3/DMSO-
d6) d 14.5, 21.3, 33.3, 34.5, 34.9, 171.6, 174.3; HRMS (CI,
i-C4H10) m/z found 158.1020 calcd for C7H15N2O 158.1055
(M1H)1.
N, N0-Dimethyl-glutaric diamide 15c. Mp 1038C; lit. 97±
988C;39 IR (KBr) cm21 1683, 1618; 1H NMR (CDCl3/
DMSO-d6) d 1.98 (m, 2H), 2.31 (m, 2H), 2.39 (m, 2H),
2.95 (d, 6H), 5.92 (bp, 1NH), 6.34 (bp, 1NH); 13C NMR
(CDCl3/DMSO-d6) d 20.8, 32.1, 34.9, 35.3, 172.5, 175.6;