tert-butyl 4-aminobenzoate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: In 150 ml of isopropyl ether was dissolved 13.51 g of 4-amino-benzoic acid t-butyl ester. To the solution was added, while stirring at room temperature, 9.83 g of ethoxycarbonyl isothiocyanate. The mixture was stirred for two hours, then the resulting crystalline precipitate was collected by filtration, followed by recrystallization from isopropyl ether to give 21.83 g of the title compound as colorless needles. To the solution was added The mixture was stirred for two hours the resulting crystalline precipitate was collected by filtration followed by recrystallization from isopropyl ether

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

Procedure: A suspension of 2-(2,2-dimethylpropionyloxymethyl)-3,4,7,8-tetrahydro-6H-cyclopenta[g]quinazolin-4,6-dione (0.47 g, 1.50 mmol) in anhydrous methanol (33 ml) and anhydrous CH2Cl2 (5 ml) was treated with tert-butyl 4-aminobenzoate (0.34 g, 1.78 mmol) followed by decaborane (0.07 g, 0.58 mmol) and the mixture stirred at room temperature under argon for 18 h. The solvent was removed in vacuo and the residue purified by column chromatography (50 g of silica gel) eluting with 30% ethyl acetate in CH2Cl2 to yield the desired product as a white solid (0.43 g, 58%); m.p. 231° C.; 1H-NMR (CDCl3) δ 1.26 (s, 9H, CMe3), 1.58 (s, 9H, CO2CMe3), 2.00 (m, 1H, 7-H), 2.72 (m, 1H, 7-H), 3.08 (m, 2H, 8-H), 5.10 (s, 2H, 2-CH2), 5.15 (m, 1H, 6-H), 6.67 (d, J=8.8 Hz, 2H, 3′-H, 5′-H), 7.58 (s, 1H, 9-H), 7.87 (d, J=8.8 Hz, 2H, 2′-H, 6′-H), 8.24 (s, 1H, 5-H); MS (FAB, m/z): Found 491 [(M+H)+, 25%], 514 [(M+Na)+, 100%]; Found C, 68.37; H, 6.86; N, 8.35. C28H33N3O5 requires C, 68.41; H, 6.77; N, 8.55%. The solvent was removed in vacuo the residue purified by column chromatography (50 g of silica gel) eluting with 30% ethyl acetate in CH2Cl2

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

Procedure: A suspension of 2-(2,2-dimethylpropionyloxymethyl)-3,4,7,8-tetrahydro-6H-cyclopenta[g]quinazolin-4,6-dione (0.47 g, 1.50 mmol) in anhydrous methanol (33 ml) and anhydrous CH2Cl2 (5 ml) was treated with tert-butyl 4-aminobenzoate (0.34 g, 1.78 mmol) followed by decaborane (0.07 g, 0.58 mmol) and the mixture stirred at room temperature under argon for 18 h. The solvent was removed in vacuo and the residue purified by column chromatography (50 g of silica gel) eluting with 30% ethyl acetate in CH2Cl2 to yield the desired product as a white solid (0.43 g, 58%); m.p. 231° C.; 1H-NMR (CDCl3) δ 1.26 (s, 9H, CMe3), 1.58 (s, 9H, CO2CMe3), 2.00 (m, 1H, 7-H), 2.72 (m, 1H, 7-H), 3.08 (m, 2H, 8-H), 5.10 (s, 2H, 2-CH2), 5.15 (m, 1H, 6-H), 6.67 (d, J=8.8 Hz, 2H, 3′-H, 5′-H), 7.58 (s, 1H, 9-H), 7.87 (d, J=8.8 Hz, 2H, 2′-H, 6′-H), 8.24 (s, 1H, 5-H); MS (FAB, m/z): Found 491 [(M+H)+, 25%], 514 [(M+Na)+, 100%]; Found C, 68.37; H, 6.86; N, 8.35. C28H33N3O5 requires C, 68.41; H, 6.77; N, 8.55%. The solvent was removed in vacuo the residue purified by column chromatography (50 g of silica gel) eluting with 30% ethyl acetate in CH2Cl2

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

Procedure: Following the General Procedure (Scheme 1), tert-butyl 4-aminobenzoate, 1, (1.0 g, 5.17 mmol), triethylamine (1.8 mL, 12.9 mmol), dichloroethane (75 mL), benzene-1,2-disulfonyl dichloride (1.7 g, 2.88 mmol) and dichloroethane afforded tert-butyl-4-(1,1,3,3-tetraoxidobenzo[d][1,3,2]dithiazol-2-yl)benzoate, 5, (0.39 g, 38%).

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

Procedure: Following the General Procedure (Scheme 1), tert-butyl 4-aminobenzoate, 1, (1.0 g, 5.17 mmol), triethylamine (1.8 mL, 12.9 mmol), dichloroethane (75 mL), benzene-1,2-disulfonyl dichloride (1.7 g, 2.88 mmol) and dichloroethane afforded tert-butyl-4-(1,1,3,3-tetraoxidobenzo[d][1,3,2]dithiazol-2-yl)benzoate, 5, (0.39 g, 38%).