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C. Sanchez-Sanchez et al. / Tetrahedron 58 (2002) 7267–7274
7273
4.3.4. With tert-butyl methyl ether. (25 mL, 200 mmol,
1 h). Unreacted phthalimide (90 mg) and photoadduct 14
(1.15 g, 78%).
(CDCl3) 7.79–7.40 (m, 4H, ArH), 6.65 (bs, 1H, NH), 6.33
(bs,0 1H, OH), 3.30 (q, 1H, J¼6.9 Hz, 0H-10), 2.61 (m, 4H,
H-3 , H-40), 1.17 (t, 6H, J¼7.1 Hz, H-5 , H-60), 0.76 (d, 3H,
J¼6.9 Hz, H20); dC (CDCl3) 170.4 (C1), 148.0 (C3a), 132.4,
129.3, 123.2, 121.6, (C4,0 C5, 0C6, C7), 1032.10 (C7a), 87.5
(C3), 61.9 (C10), 44.6 (C3 , C4 ), 13.8 (C5 , C6 ), 7.5 (C20);
m/z (EI) 230 (Mþ218, 1), 100 (100); m/z (CI, CH4) 249
[(MþH)þ, 100], 231 (17).
2,3-Dihydro-3-hydroxy-3-[(1,1-dimethylethoxy)methyl]-
1H-isoindol-1-one (14). White crystals; mp 132–1348C
(CHCL3/hexane); [Found: C, 66.41; H, 7.31; N, 5.94.
C13H17NO3 requires C 66.36, H 7.18, N 5.95]; nmax
(KBr) cm21 3228, 1678; dH (CDCl3) 7.74 (d, 1H,
J¼7.2 Hz, H-7), 7.57–7.46 (m, ArH), 6.680 (s, 1H, NH),
3.93 (s, 1H, OH), 3.80 (d, 1H, J¼8.6 Hz, H-1 ), 3.43 (d, 1H,
J¼8.6 Hz, H-10), 1.21 (s, 9H, 3£CH3); dC (CDCl3) 169.2
(C1), 146.1 (C3a), 131.3 (C7a), 132.3, 129.6, 123.5 y 122.6
(C4, C5, C6, C7), 86.4 (C3), 74.1 (C20), 66.8 (Cl0), 27.3
(CH3); m/z (EI) 217 (Mþ218, 1), 178 (8) 161 (8), 148 (100),
130 (43), 102 (10); m/z (CI, CH4) 236 [(MþH)þ, 100], 216
(55).
4.3.8. General procedure for the dehydration of photo-
adducts 10, 11, 14 and 16. A chloroform solution (50 mL)
of photoadduct (0.8 mmol) and TFA (0.1 mL, 1.3 mmol)
was stirred at 258C for 4 h. The resulting solution was
washed with saturated aqueous Na2CO3 and the organic
solution dried and concentrated in vacuo. When a single
isomer was formed, the residue was crystallized from EtOH,
EtOAc or EtOAc/hexane mixtures. When both isomers were
formed, the residue was subjected to silicagel column
chromatography (2:1 hexane/EtOAc).
4.3.5. With benzyl methyl ether. (2 mL, 16.2 mmol, 4 h).
Unreacted phthalimide (100 mg) and photoadduct 15 (1.2 g,
72%).
3-[(Z)-Phenylmethylidene]-1H-isoindol-1(2H)-one (20a).
White crystals; mp 181–1828C (EtOH); [Found: C, 81.99;
H, 4.88; N, 6.27. C15H11NO requires C 81.53, H 5.01, N
6.33]; nmax (KBr) cm21 3255, 1705; dH (CDCl3) 8.46 (bs,
1H, NH), 7.87 (d, 1H, J¼7.3 Hz, H-7), 7.79 (d, 1H,
J¼7.8 Hz, H-4), 7.63 (dt, 1H, J¼7.8,0 1.0 Hz, H-5), 7.55–
7.26 (m, 6H, ArH), 6.55 (s, 1H, H-1 ); dC (CDCl3) 169.6
(C1), 138.1, 134.6 and 132.6 (C7a, C3a, C3, C20), 0132.01,
128.8, 128.4, 127.4, 123.2, 119.6 (C4, C5, C6, C7, C3 , C7 ),
106.4 (C10); m/z (EI) 221 (Mþ, 100), 193 (21), 165 (19).
2,3-Dihydro-3-hydroxy-3-[methoxy(phenyl)methyl]-1H-
isoindol-1-one (15, mixture of isomers). White crystals; mp
180–1838C (CHCl3); [Found: C, 71.45; H, 5.70; N, 5.24.
C16H15NO3 requires C 71.36, H 5.61, N 5.10]; nmax
(neat) cm21 3348, 3199, 1678; dH (CDCl3) 7.75–6.90 (m,
18H, ArH), 6.72 (s, 1H, NH), 6.35 (s, 1H, NH), 4.59 (s, 1H,
H-10), 4.39 (s, 1H, H-10), 3.98 (s, 1H, OH), 3.61 (s, 1H, OH),
3.40 (s, 3H, OCH3), 3.28 (s, 3H, OCH3); dC (CDCl3) 169.7
(C1), 169.5 (C1), 146.1 (C3a), 145.8, (C3a), 135.3 (C20),
134.9 (C20), 131.1 (C7a), 130.8 (C7a), 131.8, 131.7, 129.1,
129.0, 128.2, 127.9, 127.8, 127.7, 127.2, 123.5, 122.8,
122.6, 122.4 (C4, C5, C6, C7, C30, C70), 88.4 (C3), 88.3
(C3), 86.9 (C10), 86.8 (C10), 56.9 (OCH3), 56.7 (OCH3); m/z
(EI) 251 (Mþ218, 2), 148 (49) 130 (60), 121 (100); m/z (CI,
CH4) 270 [(MþH)þ, 100], 252 (43).
3-[(E)-Phenylmethylidene]-1H-isoindol-1(2H)-one (20b).
White crystals; mp 172–1738C (EtOH); [Found: C, 81.81;
H, 5.14; N, 6.30. C15H11NO requires C 81.53, H 5.01, N
6.33]; nmax (KBr) cm21 3156, 1699; dH (CDCl3) 9.59 (s, 1H,
NH), 7.89 (d, 1H,0J¼7.2 Hz, H-7), 7.53–7.33 (m, 8H, ArH),
6.73 (s, 1H, H-1 ); dC (CDCl3) 168.9 (C1), 135.5, 135.0,
134.7, 131.5 (C7a, C3a, C20, C3), 1031.7, 129.4, 129.1,
128.6, 127.6, 123.3 (C4, C5, C6, C7, C3 , 40, C60, C70), 112.6
(C10); m/z (EI) 221 (Mþ, 100), 193 (24), 165 (21).
4.3.6. With N,N-dimethylaniline. (10 mL, 78.5 mmol,
2 h). Unreacted phthalimide (150 mg) and photoadduct 16
(1.1 g, 74%).
3-[(Z)-Phenoxymethylidene]-1H-isoindol-1(2H)-one (21a).
White crystals; mp 168–1708C (EtOAc/hexane); [Found: C,
75.86; H, 4.76; N, 5.85. C15H11NO2 requires C 75.94, H
4.67, N 5.90]; nmax (neat) cm21 3184, 1675; dH (CDCl3)
8.25 (s, 1H, NH), 7.90 (d, 1H, J¼7.3 Hz, H-7), 7.60–7.10
(m, 8H, ArH), 6.96 (s, 1H, H-10); dC (CDCl3) 167.0 (C1),
156.8 (C20), 136.1 (C3a), 131.8, 129.8, 128.1, 124.0,0123.08,
123.6, 118.7, 116.5 (C4, C5, C6, C7, C30, 40, C60, C7 , C1 ),
129.0 (C7a), 121.5 (C3); m/z (EI) 237 (Mþ, 100), 180 (13),
160 (35), 132 (43).
2,3-Dihydro-3-hydroxy-3-{[methyl(phenyl)amino]methyl}-
1H-isoindol-1-one (16). White crystals; mp 155–1568C
(EtOAc); [Found: C, 71.70; H, 6.11; N, 10.36. C16H16N2O2
requires C 71.62, H 6.01, N 10.44]; nmax (KBr) cm21 3211,
1689; dH (CDCl3) 7.60–6.60 (m, 9H, ArH), 7.05 (s, 1H,
NH), 4.10 (s, 1H, OH), 3.84 (d, 1H, J¼15.2 Hz, H-10), 3.57
(d, 1H, J¼15.2 Hz, H-10), 3.00 (s, 3H, NCH3); dC (CDCl3)
169.3 (C1), 149.7 (C20), 147.4 (C3a) 132.4, 129.4, 123.1,
122.6, 116.8 (C4, C5, C6, C7, C50), 128.6 (C40, C60), 112.4
(C30, C70), 130.6 (C7a), 88.4 (C3), 60.0 (C10), 39.7 (CH3);
m/z (EI) 268 (Mþ, 3), 151 (19), 130 (17), 120 (100); m/z (CI,
CH4) 269 [(MþH)þ, 100], 251 (39).
3-[(E)-Phenoxymethylidene]-1H-isoindol-1(2H)-one (21b).
White crystals; mp 145–1468C (EtOAc/hexane); [Found: C,
76.22; H, 4.79; N, 5.74. C15H11NO2 requires C 75.94, H
4.67, N 5.90]; nmax (KBr) cm21 3040, 1703; dH (CDCl3)
9.25 (s, 1H, NH), 8.12 (d, 1H, J¼7.6 Hz, H-7), 7.90 (d, 1H,
J¼7.6 Hz, H-4), 7.63 (dt, 1H, J¼7.6, 1.1 Hz, H6), 7.50 (dt,
1H, J¼7.6, 1.1 Hz, H-5), 7.44–7.13 (m, 5H, ArH), 7.10 (s,
1H, H-10); dC (CDCl3) 168.5 (C1), 157.1 (C20), 135.0 (C3a),
132.3, 129.9, 129.1, 128.7, 124.4, 123.7, 123.3, 116.4 5 (C4,
C5, C6, C7, C30, 40, C60, C70, C10) 129.7 (C7a), 123.9 (C3);
m/z (EI) 237 (Mþ, 100), 180 (12), 160 (30), 132 (35).
4.3.7. With triethylamine. (10 mL, 72.3 mmol, 2 h).
Unreacted phthalimide (101 mg) and photoadduct 17
(1.18 g, 76%).
[1-(Diethylamino)ethyl]-2,3-dihydro-3-hydroxy-1H-iso-
indol-1-one (17). White crystals; mp 172–1748C (EtOAc);
[Found: C, 67.75; H, 8.00; N, 11.14. C14H20N2O2 requires C
67.72, H 8.12, N 11.2]; nmax (neat) cm21 3189, 1693; dH