tert-butyl N-(4-amino-2-cyanophenyl)carbamate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of bromine (25.1 mmol) in dichloromethane (1.3 mL) was added dropwise, under an argon atmosphere, to a solution of amine II (27.9 mmol) in acetic acid (325 mL). After 2.5 h of stirring at room temperature, the solvent was removed in vacuo. The excess of acetic acid was co-evaporated with heptane to afford the expected compound III (10.1 g, quantitative yield) as a beige solid; mp 163° C.; IR (KBr) νmax/cm−1 3327, 2826, 2605, 2566, 2236, 1955, 1716, 1610, 1561, 1496, 1481, 1398, 1369, 1280, 1238, 1193, 1153, 1059, 963, 906, 838; 1H NMR (300 MHz, DMSO-d6) δ 9.05 (s, 1H, NH), 7.11 (d, 1H, J=8.7 Hz), 7.05 (d, 1H, J=8.7 Hz), 6.01 (s, 2H, NH2), 1.43 (s, 9H); 13C NMR (75 MHz, DMSO-d6) δ 153.6, 144.1, 131.6, 126.9, 119.6, 116.1, 112.8, 107.8, 79.5, 28.1; HRMS calcd for C12H15N3O2Br (M+H+): 312.0348, found 312.0354. the solvent was removed in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The thiazolo[5,4-f]quinazoline-2-carbonitriles VIIIaa-ib were prepared following scheme 1: N-Boc Protection of 2-amino-5-nitrobenzonitrile using di-tert-butyl dicarbonate in a suitable solvent, such as dichloromethane, in presence of suitable bases such as triethylamine and 4-(dimethylamino)pyridine and preferably at room temperature, provides tert-butyl (2-cyano-4-nitrophenyl)carbamate I in high yield. Reduction of the nitro intermediate I, for example by treatment with ammonium formate and a catalytic amount of 10% palladium charcoal preferably in ethanol under microwave irradiation for preferably 30 min at 600 W, provides tert-butyl 4-amino-2-cyanophenylcarbamate II in high yield. Treatment of intermediate II by a solution of bromine in dichloromethane in a suitable solvent, such as acetic acid, preferably at room temperature provides tert-butyl 4-amino-3-bromo-2-cyanophenylcarbamate III in a quantitative yield. Intermediate III is reacted with Appel's salt (4,5-dichloro-1,2,3-dithiazolium chloride) (Appel, R. et al., Chem. Ber., 1985, 118, 1632) preferably in dichloromethane at room temperature to afford (Z)-tert-butyl-3-bromo-4-(4-chloro-5H-1,2,3-dithiazol-5-ylideneamino)-2-cyanophenylcarbamate IV. N-Boc deprotection of intermediate IV using di-tert-butyl dicarbonate in a suitable solvent, such acetic acid, preferably under microwave irradiation at 118° C. provides (Z)-6-amino-2-bromo-3-(4-chloro-5H-1,2,3-dithiazol-5-ylideneamino)benzonitrile V in a quantitative yield. Cyclization of intermediate V may be accomplished by treatment with copper iodide in a suitable solvent, such as pyridine, preferably under microwave irradiation at 400 W at 130° C. for 20 min to obtain 6-aminobenzo[d]thiazole-2,7-dicarbonitrile VI in good yield (Besson, T. et al., J. Chem. Soc., Perkin Trans. 1, 1998, 3925). Treatment of intermediate VI in a suitable solvent, such as dimethylformamide dimethylacetal, preferably under microwave irradiation at 70° C. (600 W) gives (E)-N′-(2,7-dicyanobenzo[d]thiazol-6-yl)-N,N-dimethylformimidamide VII in good yield. Cyclization of intermediate VII in thiazolo[5,4-f]quinazoline-2-carbonitriles VIIIaa-ib may be accomplished by a Dimroth rearrangement using the appropriate aniline or primary amine R3NH2 (preferably 1.5 equivalent) in a suitable solvent, such acetic acid and preferably under microwave irradiation at 118° C. (600 W) (Foucourt, A. et al., Tetrahedron, 2010, 66, 4495). for preferably 30 min

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of bromine (25.1 mmol) in dichloromethane (1.3 mL) was added dropwise, under an argon atmosphere, to a solution of amine II (27.9 mmol) in acetic acid (325 mL). After 2.5 h of stirring at room temperature, the solvent was removed in vacuo. The excess of acetic acid was co-evaporated with heptane to afford the expected compound III (10.1 g, quantitative yield) as a beige solid; mp 163° C.; IR (KBr) νmax/cm−1 3327, 2826, 2605, 2566, 2236, 1955, 1716, 1610, 1561, 1496, 1481, 1398, 1369, 1280, 1238, 1193, 1153, 1059, 963, 906, 838; 1H NMR (300 MHz, DMSO-d6) δ 9.05 (s, 1H, NH), 7.11 (d, 1H, J=8.7 Hz), 7.05 (d, 1H, J=8.7 Hz), 6.01 (s, 2H, NH2), 1.43 (s, 9H); 13C NMR (75 MHz, DMSO-d6) δ 153.6, 144.1, 131.6, 126.9, 119.6, 116.1, 112.8, 107.8, 79.5, 28.1; HRMS calcd for C12H15N3O2Br (M+H+): 312.0348, found 312.0354. the solvent was removed in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The thiazolo[5,4-f]quinazoline-2-carbonitriles VIIIaa-ib were prepared following scheme 1: N-Boc Protection of 2-amino-5-nitrobenzonitrile using di-tert-butyl dicarbonate in a suitable solvent, such as dichloromethane, in presence of suitable bases such as triethylamine and 4-(dimethylamino)pyridine and preferably at room temperature, provides tert-butyl (2-cyano-4-nitrophenyl)carbamate I in high yield. Reduction of the nitro intermediate I, for example by treatment with ammonium formate and a catalytic amount of 10% palladium charcoal preferably in ethanol under microwave irradiation for preferably 30 min at 600 W, provides tert-butyl 4-amino-2-cyanophenylcarbamate II in high yield. Treatment of intermediate II by a solution of bromine in dichloromethane in a suitable solvent, such as acetic acid, preferably at room temperature provides tert-butyl 4-amino-3-bromo-2-cyanophenylcarbamate III in a quantitative yield. Intermediate III is reacted with Appel's salt (4,5-dichloro-1,2,3-dithiazolium chloride) (Appel, R. et al., Chem. Ber., 1985, 118, 1632) preferably in dichloromethane at room temperature to afford (Z)-tert-butyl-3-bromo-4-(4-chloro-5H-1,2,3-dithiazol-5-ylideneamino)-2-cyanophenylcarbamate IV. N-Boc deprotection of intermediate IV using di-tert-butyl dicarbonate in a suitable solvent, such acetic acid, preferably under microwave irradiation at 118° C. provides (Z)-6-amino-2-bromo-3-(4-chloro-5H-1,2,3-dithiazol-5-ylideneamino)benzonitrile V in a quantitative yield. Cyclization of intermediate V may be accomplished by treatment with copper iodide in a suitable solvent, such as pyridine, preferably under microwave irradiation at 400 W at 130° C. for 20 min to obtain 6-aminobenzo[d]thiazole-2,7-dicarbonitrile VI in good yield (Besson, T. et al., J. Chem. Soc., Perkin Trans. 1, 1998, 3925). Treatment of intermediate VI in a suitable solvent, such as dimethylformamide dimethylacetal, preferably under microwave irradiation at 70° C. (600 W) gives (E)-N′-(2,7-dicyanobenzo[d]thiazol-6-yl)-N,N-dimethylformimidamide VII in good yield. Cyclization of intermediate VII in thiazolo[5,4-f]quinazoline-2-carbonitriles VIIIaa-ib may be accomplished by a Dimroth rearrangement using the appropriate aniline or primary amine R3NH2 (preferably 1.5 equivalent) in a suitable solvent, such acetic acid and preferably under microwave irradiation at 118° C. (600 W) (Foucourt, A. et al., Tetrahedron, 2010, 66, 4495). for preferably 30 min

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of bromine (25.1 mmol) in dichloromethane (1.3 mL) was added dropwise, under an argon atmosphere, to a solution of amine II (27.9 mmol) in acetic acid (325 mL). After 2.5 h of stirring at room temperature, the solvent was removed in vacuo. The excess of acetic acid was co-evaporated with heptane to afford the expected compound III (10.1 g, quantitative yield) as a beige solid; mp 163° C.; IR (KBr) νmax/cm−1 3327, 2826, 2605, 2566, 2236, 1955, 1716, 1610, 1561, 1496, 1481, 1398, 1369, 1280, 1238, 1193, 1153, 1059, 963, 906, 838; 1H NMR (300 MHz, DMSO-d6) δ 9.05 (s, 1H, NH), 7.11 (d, 1H, J=8.7 Hz), 7.05 (d, 1H, J=8.7 Hz), 6.01 (s, 2H, NH2), 1.43 (s, 9H); 13C NMR (75 MHz, DMSO-d6) δ 153.6, 144.1, 131.6, 126.9, 119.6, 116.1, 112.8, 107.8, 79.5, 28.1; HRMS calcd for C12H15N3O2Br (M+H+): 312.0348, found 312.0354. the solvent was removed in vacuo

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The thiazolo[5,4-f]quinazoline-2-carbonitriles VIIIaa-ib were prepared following scheme 1: N-Boc Protection of 2-amino-5-nitrobenzonitrile using di-tert-butyl dicarbonate in a suitable solvent, such as dichloromethane, in presence of suitable bases such as triethylamine and 4-(dimethylamino)pyridine and preferably at room temperature, provides tert-butyl (2-cyano-4-nitrophenyl)carbamate I in high yield. Reduction of the nitro intermediate I, for example by treatment with ammonium formate and a catalytic amount of 10% palladium charcoal preferably in ethanol under microwave irradiation for preferably 30 min at 600 W, provides tert-butyl 4-amino-2-cyanophenylcarbamate II in high yield. Treatment of intermediate II by a solution of bromine in dichloromethane in a suitable solvent, such as acetic acid, preferably at room temperature provides tert-butyl 4-amino-3-bromo-2-cyanophenylcarbamate III in a quantitative yield. Intermediate III is reacted with Appel's salt (4,5-dichloro-1,2,3-dithiazolium chloride) (Appel, R. et al., Chem. Ber., 1985, 118, 1632) preferably in dichloromethane at room temperature to afford (Z)-tert-butyl-3-bromo-4-(4-chloro-5H-1,2,3-dithiazol-5-ylideneamino)-2-cyanophenylcarbamate IV. N-Boc deprotection of intermediate IV using di-tert-butyl dicarbonate in a suitable solvent, such acetic acid, preferably under microwave irradiation at 118° C. provides (Z)-6-amino-2-bromo-3-(4-chloro-5H-1,2,3-dithiazol-5-ylideneamino)benzonitrile V in a quantitative yield. Cyclization of intermediate V may be accomplished by treatment with copper iodide in a suitable solvent, such as pyridine, preferably under microwave irradiation at 400 W at 130° C. for 20 min to obtain 6-aminobenzo[d]thiazole-2,7-dicarbonitrile VI in good yield (Besson, T. et al., J. Chem. Soc., Perkin Trans. 1, 1998, 3925). Treatment of intermediate VI in a suitable solvent, such as dimethylformamide dimethylacetal, preferably under microwave irradiation at 70° C. (600 W) gives (E)-N′-(2,7-dicyanobenzo[d]thiazol-6-yl)-N,N-dimethylformimidamide VII in good yield. Cyclization of intermediate VII in thiazolo[5,4-f]quinazoline-2-carbonitriles VIIIaa-ib may be accomplished by a Dimroth rearrangement using the appropriate aniline or primary amine R3NH2 (preferably 1.5 equivalent) in a suitable solvent, such acetic acid and preferably under microwave irradiation at 118° C. (600 W) (Foucourt, A. et al., Tetrahedron, 2010, 66, 4495). for preferably 30 min