Cationic and mesoionic 1,3-thiazolo-[3,2-c]quinazoline derivatives

Article abstract of DOI:10.1002/hc.10148

4-Allylthio-2-arylquinazolines 4a-c undergo cyclization by action of bromine to furnish 5-aryl-3-bromomethyl-2,3-dihydrothiazolo[3,2-c]quinazolin-4-ium bromides 5a-c. Compounds 5a-c undergo ring opening by action of water under acid catalysis to afford the corresponding dibromide derivatives 6a-c. Bromination of 3-allyl-2-aryl-4(3H)quinazolinethiones 7a-c leads to 5-aryl-2-bromomethyl-2,3-dihydrothiazolo[3,2-c]quinazolin-4-ium bromides 8a-c. However, anhydro-3-hydroxy-5-aryl-1,3-thiazolo[3,2-c]quinazolin-4-ium hydroxide 10a-c were prepared by the cyclodehydration of the corresponding thioglycolic acids 9a-c with Ac₂O.

Full text of DOI:10.1002/hc.10148

Heteroatom Chemistry
Volume 14, Number 7, 2003
Cationic and Mesoionic 1,3-Thiazolo-
[3,2-c]quinazoline Derivatives
A. A. F. Wasfy
Chemistry Department, Faculty of Science, Benha University, Benha, Egypt
Received 22 October 2002; revised 28 November 2002
investigated the behavior of the quinazoline-4(3H)-
ABSTRACT: 4-Allylthio-2-arylquinazolines 4a–c
undergo cyclization by action of bromine to furnish
5-aryl-3-bromomethyl-2,3-dihydrothiazolo[3,2-c]qui-
nazolin-4-ium bromides 5a–c. Compounds 5a–c
undergo ring opening by action of water under acid
catalysis to afford the corresponding dibromide
derivatives 6a–c. Bromination of 3-allyl-2-aryl-
4(3H)quinazolinethiones 7a–c leads to 5-aryl-2-
bromomethyl-2,3-dihydrothiazolo[3,2-c]quinazolin-
4-ium bromides 8a–c. However, anhydro-3-hydroxy-
5-aryl-1,3-thiazolo[3,2-c]quinazolin-4-ium hydroxide
10a–c were prepared by the cyclodehydration of
the corresponding thioglycolic acids 9a–c with
thione derivatives 3a–c towards unsaturated alkylat-
ing reagents in different reaction conditions. Unsat-
urated S- and N-alkyl derivatives were aimed for the
synthesis of the title compounds.
Three representative members of quinazoline-
4(3H)-thiones [3] 3 (R = benzyl, 2-chlorophenyl,
2-naphthyl) were selected for the present investi-
gation and these were conveniently prepared by
heating of the corresponding 4H-3,1-benzothiazine-
4-thiones [4] 2, readily available from direct thia-
tion of 3,1-benzoxazin-4-one derivatives [5] 1, with
formamide at 150◦C. We now report the synthe-
sis of otherwise not available cationic derivatives
of the thiazolo[3,2-c]quinazoline ring system. It
has been briefly mentioned [6,7], that thiazolo[3,2-
c]quinazolinum cations are intermediates in the
preparation of 2-(o-aminophenyl)thiazoles from 2-
(4-quinazolinylthio)acetophenones and perchloric
acid or phosphoryl chloride.
ꢀ
C
Ac2O.
2003 Wiley Periodicals, Inc. Heteroatom Chem
14:576–580, 2003; Published online in Wiley InterScience
(www.interscience.wiley.com). DOI 10.1002/hc.10148
INTRODUCTION
The rational approach to thiazolo[3,2-c]quina-
zolinium cations is based on the cyclization of
S- and N-allyl derivatives 4a–c and 7a–c of
quinazoline-4(3H)-thiones 3a–c. In this type of com-
pounds the allylic side-chain can provide a secondary
carbonium ion appropriately placed for attack of N-3
or exocyclic S to form the thiazole ring.
As alkylation in heterocyclic thioureas with an
exocyclic thio function proceeds at the sulfur atom,
4-allylthioquinazolines 4a–c are obtained in excel-
lent yields from 2-benzyl-, 2-(2-chlorophenyl)-, or
2-(2-naphthyl)-4(3H)-quinazolinethiones (3a–c) and
allyl bromide in the presence of triethylamine. Com-
pounds 4a–c undergo ring closure by action of
bromine in glacial acetic acid at room temperature
to furnish the corresponding 3-bromomethyl-2,
We previously reported [1] the synthesis of bridge-
head nitrogen heterocycles of neutral character
which contain the quinazoline moiety, e.g., 3-
oxo-2H-imidazo[1,2-c]- and 4-oxo-2H,3H-pyrimido-
[1,2-c]quinazolines. In this context we wish to com-
municate here the synthesis of some new cationic or
mesoionic annelated derivatives of the thiazolo[3,2-
c]quinazoline ring system based on quinazoline-
4(3H)-thione. In continuation of our studies on
ꢀ
thione
thiol tautomeric equilibria in hetero-
ꢁ
cyclic diazines namely, quinazoline-4(3H)-thione
[1] and pyrimidine-2(1H)-thione [2], we have now
Correspondence to: A. A. F. Wasfy; e-mail: wasfy588@hotmail.
com.
c
ꢀ
2003 Wiley Periodicals, Inc.
576

Cationic and Mesoionic 1,3-Thiazolo[3,2-c]quinazoline Derivatives 577
3-dihydrothiazolo-[3,2-c]quinazolin-4-ium bromide
5a–c in good yield.
Compounds 5a–c undergo ring opening of
the thiazole moiety by action of water under acid
catalysis to furnish the corresponding (2,3-dibromo-
propyl)thioquinazolines 6a–c in moderate yields.
Attempts to prepare the N-allyl derivatives 7a–c by
direct allylation of quinazoline-4(3H)-thiones 3a–c
is impeded by the preferential reactivity of the sulfur
atom. In consequence of that, the regioisomers
of 4a–c, 3-allyl-4(3H)-quinazolinethiones 7a–c
have been prepared in good yields by the reaction
of the 4H-3,1-benzothiazine-4-thiones 2a–c with
allylamine. In agreement with the reported results
[8], bromination of 7a–c in acetic acid solution
at room temperature gave 2-bromomethyl-2,3-
dihydrothiazolo[3,2-c]-quinazolin-4-ium bromides
8a–c in good yields.
A variety of monocyclic mesoionic compounds
are known [9], but derivatives containing fused
mesoionic rings are less common, especially those
with the second ring heteroaromatic [10]. The
author has now attempted to synthesize some
of fused-ring mesoionic systems based on 4(3H)-
quinzolinethiones. The condensation of 4(3H)-
quinazolinethiones 3a–c with bromoacetic acid
under basic condition readily gave the correspond-
ing carboxymethylthio derivatives 9a–c, in fair
yields, and these were smoothly converted into
the corresponding mesoionic 1,3-thiazolo[3,2-c]-
4-quinazolinium-3-ones 10a–c by treatment with
acetic anhydride in the presence or absence of
Et3N.
SCHEME 1
2a: Yield 5.6 g (30%), mp 147–149◦C (lit. [4]
148◦C); IR (cm−1): 2910 (alkyl-H), 1620 (C N), 1325
(C S). Found: C, 66.92; H, 4.38; N, 5.42%. Calcd for
C15H11NS2: C, 66.88; H, 4.12; N, 5.20%.
The structural assignments of all the compounds
(Scheme 1) were based on elemental analyses and
characteristic IR and 1H NMR spectral data.
2b: Yield 8.7 g (43%), mp 144–146◦C (lit. [4]
145◦C); IR (cm−1): 1615 (C N), 1310 (C S). Found:
C, 58.30; H, 2.82; N, 4.91%. Calcd for C14H8ClNS2: C,
58.02; H, 2.78; N, 4.83%.
EXPERIMENTAL
Melting points were taken in open capillary tubes
and were uncorrected. IR spectra in KBr were
recorded on a shimadzu 470 spectrophotometer and
1H NMR spectra were recorded on a JOEL Fx 90 Q9
spectrometer using TMS as an internal reference.
Mass spectra were recorded on an HP Model MS
5988 spectrometer.
2c: Yield 10.6 g (50%), mp 155–157◦C (lit. [4]
157◦C); IR (cm−1): 1610 (C N), 1295 (C S). Found:
C, 70.84; H, 3.82; N, 4.62%. Calcd for C18H11NS2: C,
70.79; H, 3.63; N, 4.59%.
2-Benzyl-, 2-Chlorophenyl-, or 2-Naphthyl-
4(3H)-quinazolinethione (3a–c)
A mixture of 2a–c (0.024 mol) and formamide (1.2
ml, 0.03 mol) was heated in an oil bath at 150◦C for
4 h. The resulting solid product was cooled and crys-
tallized from ethanol to furnish 3a–c.
2-Benzyl-, 2-Chlorophenyl-, or 2-Naphthyl-4H-3,
1-benzothiazine-4-thione (2a–c)
These were prepared from 1a–c (0.07 mol) and phos-
phorus pentasulphide (0.14 mol) according to liter-
ature [4]. Recrystallization from benzene furnished
2a–c.
3a: Yield 3.6 g (59%), mp 220–222◦C (lit. [3]
221◦C); IR (cm−1): 3300–3240 (NH), 2960 (alkyl-
1
H), 2560 (SH), 1625 (C C), 1260 (C S); H NMR

578 Wasfy
(CDCl3): ꢀ = 3.36 (s, 2H, CH2Ph), 7.11–8.74 (m, 9H,
Ar H and quinazoline ring), 9.52 (s, 1H, NHC S,
ratio 55.8), 11.14 (s, 1H, SH, ratio 44.2). Found: C,
71.48; H, 4.82; N, 11.22%. Calcd for C15H12N2S: C,
71.40; H, 4.79; N, 11.10%.
3-Bromomethyl-5-benzyl-, 5-(2-Chlorophenyl)-,
or 5-(2-Naphthyl)-2,3-dihydrothiazolo[3,2-c]-
quinazolin-4-ium bromide (5a–c)
A solution of bromine (1 g, 6.3 mmol) in acetic acid
(20 ml) was added dropwise to a well-stirred solution
of the appropriate quinazoline 4a–c (6 mmol) in the
same solvent (20 ml) at room temperature. When
the addition was completed, the yellow precipitate
which gradually separated during the reaction, was
filtered off, washed several times with diethyl ether
and crystallized from ethanol to furnish 5a–c.
3b: Yield 3.7 g (57%), mp 204–206◦C (lit. [3]
206◦C); IR (cm−1): 3340–3210 (NH), 2550 (SH), 1615
(C C), 1255 (C S). Found: C, 61.71; H, 3.39; N,
10.20%. Calcd for C14H9ClN2S: C, 61.65; H, 3.33; N,
10.27%.
3c: Yield 3.8 g (55%), mp 219–220◦C (lit. [3]
219.5◦C); IR (cm−1): 3280–3170 (NH), 2570 (SH),
1618 (C C), 1250 (C S). Found: C, 74.87; H, 4.22;
N, 9.94%. Calcd for C18H12N2S: C, 74.97; H, 4.19; N,
9.71%.
5a: Yield 1.7 g (64%), mp 192–194◦C, color-
less needles; IR (cm−1): 2940, 1610, 1590, 1576,
1559, 1489, 1425, 1400, 1342, 1290, 1170, 1050, 960,
886, 850, 718, 660; 1H NMR (CDCl3 + CF3CO2H):
ꢀ = 3.25–3.65 (m, with interference, 4H, CH2Br and
CH2Ph), 4.04–4.84 (m, 2H, SCH2), 6.25–6.85 (m,
1H, CHCH2Br), 7.40–8.50 (m, 9H, Ar H); MS (70
eV): m/z (%) = 373 (M+ + 2) (6), 371 (M+) (8), 219
(100). Found: C, 47.94; H, 3.67; N, 6.28%. Calcd for
C18H16Br2N2S: C, 47.81; H, 3.57; N, 6.19%.
4-Allylthio-2-benzyl-, 2-(2-Chlorophenyl)-,
or 2-(2-Naphthyl)quinazoline (4a–c)
To a solution of the appropriate thione 3a–c (8 mmol)
in benzene (50 ml), triethylamine (1.2 ml, 8.6 mmol)
and allyl bromide (0.7 ml, 8.3 mmol) were added; af-
ter 4 h of heating under reflux, triethylammonium
bromide was deposited. After cooling, the salt was
separated by filtration and the filterate concentrated
to dryness to afford a crude product which recrystal-
lized from ethanol to give 4a–c.
5b: Yield 1.7 g (62%), mp 176–178◦C, yellow nee-
dles; IR (cm−1): 2935, 1610, 1590, 1560, 1500, 1440,
1400, 1309, 1290, 1140, 1082, 1012, 950, 880, 760,
685; 1H NMR (CDCl3 + CF3CO2H): ꢀ = 3.35–3.68 (m,
2H, CH2Br), 3.95–5.04 (m, 2H, SCH2), 6.40–6.90 (m,
1H, CHCH2Br), 7.28–8.45 (m, 8H, Ar H); MS (70
eV): m/z (%) = 393 (M+ + 2) (4), 391 (M+) (5), 239
(100). Found: C, 43.42; H, 2.88; N, 5.66%. Calcd for
C17H13Br2ClN2S: C, 43.20; H, 2.77; N, 5.93%.
4a: Yield 2.1 g (90%), mp 71–73◦C, yellow nee-
dles; IR (cm−1): 2920, 1539, 1480, 1447, 1340, 1313,
1
990, 927, 860, 770, 765; H NMR (CDCl3): ꢀ = 3.32
5c: Yield 1.7 g (60%), mp 223–225◦C, yellow nee-
dles; IR (cm−1): 2960, 1625, 1560, 1546, 1480, 1410,
1370, 1340, 1248, 1170, 1040, 990, 830, 790, 730,
625; 1H NMR (CDCl3 + CF3CO2H): ꢀ = 3.32–3.70 (m,
2H, CH2Br), 3.90–4.89 (m, 2H, SCH2), 6.30–6.78 (m,
1H, CHCH2Br), 7.22–8.32 (m, 11H, Ar H); MS (70
eV): m/z (%) = 409 (M+ + 2) (8), 407 (M+) (5), 255
(100). Found: C, 51.94; H, 3.60; N, 5.88%. Calcd for
C21H16Br2N2S: C, 51.66; H, 3.30; N, 5.74%.
(s, 2H, CH2Ph), 4.10 (d, 2H, J = 7.1 Hz, SCH2), 5.18–
5.74 (m, 2H, CH CH2), 5.90–6.55 (m, 1H, CH CH2),
7.28–8.60 (m, 9H, Ar H); MS (70 eV): m/z (%) = 293
(M+ + 1) (18), 292 (M+) (38), 291 (100). Found: C,
73.81; H, 5.34; N, 9.62%. Calcd for C18H16N2S: C,
73.94; H, 5.52; N, 9.58%.
4b: Yield 2.2 g (88%), mp 64–66◦C, yellow nee-
dles; IR (cm−1): 1590, 1584, 1475, 1360, 1340, 1200,
1
1080, 1019, 960, 817, 760, 710; H NMR (CDCl3):
ꢀ = 4.22 (d, 2H, J = 7.1 Hz, SCH2), 5.10–5.66 (m, 2H,
CH CH2), 5.80–6.44 (m, 1H, CH CH2), 7.42–8.34
(m, 8H, Ar H); MS (70 eV): m/z (%) = 314 (M+ + 2)
(17), 313 (40), 312 (M+) (36), 311 (100). Found: C,
65.20; H, 4.24; N, 8.88%. Calcd for C17H13ClN2S: C,
65.27; H, 4.19; N, 8.96%.
2-Benzyl-, 2-(2-Chlorophenyl)-, or
2-(2-Naphthyl)-4-[(2,3-dibro-
mopropyl)thio]quinazoline (6a–c)
A solution of the appropriate bromide 5a–c (2.5
mmol) in acetic acid/water (60 ml, 2:1, v/v) was
stirred at room temperature for 6 h. The solution was
poured into ice and the resultant precipitated solid
was filtered, washed with water, and recrystallized
from acetone to give 6a–c.
4c: Yield 2.3 g (87%), mp 85–87◦C, yellow nee-
dles; IR (cm−1): 1620, 1558, 1530, 1480, 1382, 1300,
1250, 1107, 990, 907, 830, 790, 755; 1H NMR (CDCl3):
ꢀ = 4.20 (d, 2H, J = 7.1 Hz, SCH2), 5.12–5.62 (m, 2H,
CH CH2), 5.92–6.66 (m, 1H, CH CH2), 7.44–8.42
(m, 11H, Ar H); MS (70 eV): m/z (%) = 329 (M+ + 1)
(11), 328 (M+) (36), 327 (100). Found: C, 76.74; H,
4.68; N, 8.64%. Calcd for C21H16N2S: C, 76.80; H, 4.91;
N, 8.53%.
6a: Yield 0.47 g (42%), mp 114–116◦C, color-
less needles; IR (cm−1): 2950, 1618, 1558, 1544,
1480, 1442, 1344, 1318, 1255, 1190, 1030, 994, 860,
840, 772, 658; 1H NMR (CDCl3): ꢀ = 3.34 (s, 2H,

Cationic and Mesoionic 1,3-Thiazolo[3,2-c]quinazoline Derivatives 579
CH2Ph), 3.75–4.45 (m, 4H, CH2CHBrCH2Br), 4.58–
5.12 (m, 1H, CHBr), 7.35–8.65 (m, 9H, Ar H); MS
(70 eV): m/z (%) = 452 (M+ + 2) (7), 450 (M+) (4),
219 (100). Found: C, 47.94; H, 3.78; N, 6.49%. Calcd
for C18H16Br2N2S: C, 47.81; H, 3.57; N, 6.19%.
CH2 CH CH2), 5.70–6.50 (m, 1H, CH CH2), 7.30–
8.10 (m, 11H, Ar H); MS (70 eV): m/z (%) = 329
(M+ + 1) (12), 328 (M+) (41), 327 (100). Found: C,
76.77; H, 4.67; N, 8.66%. Calcd for C21H16N2S: C,
76.80; H, 4.91; N, 8.53%.
6b: Yield 0.47 g (40%), mp 128–130◦C, colorless
needles; IR (cm−1): 2935, 1618, 1585, 1565, 1542,
1530, 1450, 1401, 1342, 1318, 1250, 1170, 1082, 1030,
2-Bromomethyl-5-benzyl-, 5-(2-Chlorophenyl)-,
or 5-(2-Naphthyl)-2,3-dihydrothiazolo[3,2-c]-
quinazolin-4-ium bromide (8a–c)
1
871, 792, 735, 700; H NMR (CDCl3): ꢀ = 3.82–4.28
(m, 4H, CH2CHBrCH2Br), 4.45–4.95 (m, 1H, CHBr),
7.27–8.54 (m, 8H, Ar H); MS (70 eV): m/z (%) =
474 (M+ + 4) (4), 472 (M+ + 2) (8), 470 (M+) (5), 239
(100). Found: C, 43.42; H, 2.93; N, 5.79%. Calcd for
C17H13Br2ClN2S: C, 43.20; H, 2.77; N, 5.93%.
A solution of bromine (0.9 g, 5.6 mmol) in acetic acid
(15 ml) was added dropwise to a well-stirred solution
of the appropriate thione 7a–c (5 mmol) in the same
solvent (25 ml) at room temperature. The reaction
mixture was stirred at room temperature for 3 h and
the yellow solid which gradually separated during
the reaction was collected by filtration, washed with
water, and recrystallized from methanol to give 8a–c.
8a: Yield 1.5 g (67%), mp 238–240◦C, color-
less needles; IR (cm−1): 2954, 1618, 1590, 1560,
1480, 1350, 1300, 1245, 1029, 966, 825, 788, 727,
6c: Yield 0.53 g (44%), mp 134–136◦C, color-
less needles; IR (cm−1): 2970, 1625, 1560, 1540,
1501, 1456, 1349, 1262, 1160, 1020, 840, 780,
1
718, 685; H NMR (CDCl3): ꢀ = 3.66–4.37 (m, 4H,
CH2CHBrCH2Br), 4.45–4.82 (m, 1H, CHBr), 7.39–
8.66 (m, 11H, Ar H); MS (70 eV): m/z (%) = 488
(M+ + 2) (10), 486 (M+) (7), 255 (100). Found: C,
51.88; H, 3.60; N, 5.89%. Calcd for C21H16Br2N2S: C,
51.66; H, 3.30; N, 5.74%.
1
628; H NMR (CDCl3 + CF3CO2H): ꢀ = 3.36 (s, 2H,
CH2Ph), 3.68–4.18 (m, 2H, CH2Br), 4.95–5.70 (m, 3H,
N+ CH2 CH), 7.38–8.54 (m, 9H, Ar H); MS (70
eV): m/z (%) = 373 (M+ + 2) (6), 371 (M+) (7), 219
(100). Found: C, 47.90; H, 3.68; N, 6.25%. Calcd for
C18H16Br2N2S: C, 47.81; H, 3.57; N, 6.19%.
3-Allyl-2-benzyl-, 2-(2-Chlorophenyl)-,
or 2-(2-Naphthyl)-4(3H)-quinazolinethione
(7a–c)
8b: Yield 1.48 g (63%), mp 281–283◦C, colorless
needles; IR (cm−1): 2940, 1625, 1590, 1560, 1480,
1405, 1345, 1305, 1094, 1025, 826, 770, 728, 709;
1H NMR (CDCl3 + CF3CO2H): ꢀ = 3.78–4.26 (m, 2H,
CH2Br), 5.14–5.77 (m, 3H, N+ CH2 CH), 7.40–
8.56 (m, 8H, Ar H); MS (70 eV): m/z (%) = 393
(M+ + 2) (8), 391 (M+) (4), 239 (100). Found: C,
43.47; H, 2.84; N, 5.69%. Calcd for C17H13Br2ClN2S:
C, 43.20; H, 2.77; N, 5.93%.
To a suspension of the appropriate 1,3-benzothia-
zine-4(H)-thione 2a–c (8 mmol) in ethanol (50 ml),
allylamine (0.7 ml, 9.4 mmol) was added. The reac-
tion mixture was refluxed for 2 h. After cooling at
0◦C, the yellow precipitated solid was collected by
filtration and the crude product recrystallized from
ethanol to give 7a–c.
7a: Yield 1.8 g (77%), mp 110–112◦C, yellow
needles; IR (cm−1): 2965, 1575, 1520, 1470, 1350,
1330, 1210, 940, 910, 850, 760, 650; 1H NMR
(CDCl3): ꢀ = 3.38 (s, 2H, CH2Ph), 4.70–5.60 (m, 4H,
CH2 CH CH2), 5.90–6.50 (m, 1H, CH CH2), 7.18–
8.22 (m, 9H, Ar H); MS (70 eV): m/z (%) = 292 (M+)
(25), 219 (100). Found: C, 73.80; H, 5.58; N, 9.46%.
Calcd for C18H16N2S: C, 73.94; H, 5.52; N, 9.58%.
7b: Yield 2 g (80%), mp 115–117◦C, yellow nee-
dles; IR (cm−1): 1620, 1560, 1540, 1480, 1420, 1338,
1080, 1000, 990, 880, 790, 730, 690; 1H NMR (CDCl3):
ꢀ = 4.72–5.58 (m, 4H, CH2 CH CH2), 5.75–6.45 (m,
1H, CH CH2), 7.25–8.18 (m, 8H, Ar H); MS (70 eV):
m/z (%) = 314 (M+ + 2) (14), 313 (22), 312 (M+) (40),
297 (100). Found: C, 65.27; H, 4.25; N, 8.84%. Calcd
for C17H13ClN2S: C, 65.27; H, 4.19; N, 8.96%.
8c: Yield 1.58 g (65%), mp 225–227◦C, colorless
needles; IR (cm−1): 2928, 1615, 1557, 1522, 1478,
1404, 1346, 1255, 1178, 1020, 960, 842, 775, 740, 620;
1H NMR (CDCl3 + CF3CO2H): ꢀ = 3.75–4.15 (m, 2H,
CH2Br), 4.90–5.80 (m, 3H, N+ CH2 CH), 7.43–
8.70 (m, 11H, Ar H); MS (70 eV): m/z (%) = 409
(M+ + 2) (6), 407 (M+) (7), 255 (100). Found: C, 51.90;
H, 3.62; N, 5.84%. Calcd for C21H16Br2N2S: C, 51.66;
H, 3.30; N, 5.74%.
4-Carboxymethylthio-2-benzyl-, 2-(2-Chloro-
phenyl)-, or 2-(2-Naphthyl)quinazoline (9a–c)
Thiones 3a–c (4.5 mmol) and bromoacetic acid (0.63
g, 4.5 mmol) in anhydrous benzene (50 ml) were
treated with Et3N (0.64 ml, 4.6 mmol) and stirred
overnight at room temperature. The solution was fil-
tered to remove all Et3N·HBr, and the benzene was
evaporated in vacuo. The products 9a–c were finally
7c: Yield 2 g (77%), mp 127–129◦C, yellow
needles; IR (cm−1): 1618, 1570, 1557, 1470, 1365,
1342, 1210, 1118, 1030, 950, 912, 810, 762, 724,
620; 1H NMR (CDCl3): ꢀ = 4.75–5.52 (m, 4H,

580 Wasfy
obtained as small yellow needles by recrystallization
from ethanol.
2H, CH2Ph), 7.30–8.66 (m, 10H, Ar H); MS (70 eV):
m/z (%) = 292 (M+) (22), 219 (100). Found: C, 69.62;
H, 4.22; N, 9.61%. Calcd for C17H12N2OS: C, 69.84;
H, 4.14; N, 9.58%.
9a: Yield 1 g (72%), mp 176–178◦C; IR (cm−1)
(br) 3500–3400, 1710, 1620, 1542, 1464, 1420, 1320,
1
1090, 980, 920, 845, 770, 690; H NMR (Me2SO-d6):
10b: Yield 0.39 g (63%), mp 269–271◦C; IR
(cm−1): 1654s (polarized CO), 1625, 1598, 1582, 1557,
1471, 1360, 1340, 1206, 1088, 1016, 961, 822, 769,
ꢀ = 3.41 (s, 2H, CH2Ph), 4.46 (s, 2H, SCH2CO), 7.40–
8.55 (m, 9H, Ar H); MS (70 eV): m/z (%) = 310 (M+)
(18), 266 (22), 219 (100). Found: C, 65.55; H, 4.29; N,
9.22%. Calcd for C17H14N2O2S: C, 65.79; H, 4.55; N,
9.03%.
1
720; H NMR (Me2SO-d6): ꢀ = 7.22–8.64 (m, 9H, Ar
H); MS (70 eV): m/z (%) = 314 (M+ + 2) (6), 312 (M+)
(12), 239 (100). Found: C, 61.62; H, 2.82; N, 8.76%.
Calcd for C16H9ClN2OS: C, 61.44; H, 2.90; N, 8.96%.
10c: Yield 0.38 g (58%), mp 292–294◦C; IR
(cm−1): 1659s (polarized CO), 1619, 1597, 1552, 1529,
1352, 1304, 1207, 1185, 1145, 991, 975, 835, 816,
9b: Yield 1 g (70%), mp 161–163◦C; IR (cm−1)
(br) 3540–3425, 1715, 1618, 1590, 1572, 1470, 1365,
1320, 1210, 1180, 1002, 980, 828, 750, 680; 1H NMR
(Me2SO-d6): ꢀ = 4.37 (s, 2H, SCH2CO), 7.35–8.62 (m,
8H, Ar H); MS (70 eV): m/z (%) = 330 (M+) (22), 286
(42), 239 (100). Found: C, 58.33; H, 3.53; N, 8.62%.
Calcd for C16H11ClN2O2S: C, 58.10; H, 3.35; N, 8.47%.
9c: Yield 1 g (68%), mp 182–184◦C; IR (cm−1)
(br) 3560–3414, 1705, 1628, 1590, 1530, 1490, 1381,
1
769, 719, 645; H NMR (Me2SO-d6): ꢀ = 7.45–8.62
(m, 12H, Ar H); MS (70 eV): m/z (%) = 330 (M+ + 2)
(8), 328 (M+) (14), 255 (100). Found: C, 73.30; H,
3.78; N, 8.64%. Calcd for C20H12N2OS: C, 73.15; H,
3.68; N, 8.53%.
1
1310, 1270, 1100, 982, 910, 840, 780, 750, 690; H
NMR (Me2SO-d6): ꢀ = 4.40 (s, 2H, CH2), 7.28–8.48
(m, 11H, Ar H); MS (70 eV): m/z (%) = 346 (M+)
(25), 302 (19), 255 (100). Found: C, 69.44; H, 4.32; N,
8.22%. Calcd for C20H14N2O2S: C, 69.35; H, 4.10; N,
8.10%.
REFERENCES
[1] Wasfy, A. A. F. Phosphorus Sulfur Silicon 2002, 177,
1349.
[2] Wasfy, A. A. F.; Amine, M. S.; Eissa, A. M. F. Hetero-
cyclic Commun 1996, 2, 375.
[3] Legrand, L.; Lozac’h, N. Bull Soc Chim Fr 1961, 618.
[4] Legrand, L. Bull Soc Chim Fr 1960, 337.
[5] Bain, D. I.; Smalley, R. K. J Chem Soc C 1968, 1593.
[6] Singh, H.; Aggarwal, S. K.; Malhotra, N. Heterocycles
1984, 22, 353.
Anhydro-3-hydroxy-5-benzyl-, 5-(2-Chloro-
phenyl)-, or 5-(2-Naphthyl)-1,3-thiazolo[3,2-c]-
quinazolin-4-ium Hydroxide (10a–c)
[7] Singh, H.; Deep, K. Tetrahedron 1984, 40, 4937.
[8] Molina, P.; Alajarin, M.; Perez de Vega, M. J. Synth
Commun 1983, 933.
[9] Ohta, M.; Kato, H. In Non-Benzenoid Aromatics;
Snyder, J. P. (Ed.); Academic Press: New York, 1966;
p. 117; Ollis, W. D.; Ramsden, C. A. Adv Heterocycl
Chem 1976, 19, 3; Newton, C. J.; Ramsden, C. A. Tetra-
hedron 1982, 38, 2965; Osterhout, M. H.; Nadler, W.
R.; Padwa, A. Synthesis 1994, 123.
The thioglycolic acids 9a–c (2 mmol) were added to
a mixture of Ac2O (3 ml) and Et3N (3 ml). After the
mixture was stirred for 15 min, anhydrous ether was
added (20 ml). The dark-red solids of 10a–c recrystal-
lized from chloroform/cyclohexane, giving dark-red
needles.
10a: Yield 0.38 g (65%), mp 286–288◦C; IR
(cm−1): 1648s (polarized CO), 1620, 1602, 1562, 1545,
1489, 1420, 1347, 1338, 1310, 1245, 1170, 1040, 990,
835, 791, 730, 622; 1H NMR (Me2SO-d6): ꢀ = 3.51 (s,
[10] Mackay, D.; Wong, L. L. Can J Chem 1975, 53, 1973;
Preston, P. N.; Turnbull, K. J Chem Soc Perkin I 1977,
1229.