The reaction of 5-bromo-1,3-benzodioxole (I) with (S)-(-)-propylene oxide (II) by means of sec-butyllithium in THF gives the (S)-isopropanol derivative (IV) (also obtained by stereoselective reduction of 1-(1,3-benzodioxol-5-yl)-2-propanone (III) with Z. rouxii ATCC 14462 in a phosphate buffer). The cyclization of (IV) with 4-nitrobenzaldehyde (V) by means of HCl in hot toluene yields the benzopyran (VI), which is oxidized with air in aqueous NaOH affording the carbinol (VII). The reaction of (VII) with acetohydrazide (VIII) and HCl in refluxing ethanol gives the acetyl hydrazone (IX), which is mesylated at the secondary OH group with methanesulfonyl chloride and TEA in dichloromethane yielding the mesylate (X). The cyclization of (X) by means of NaOH in methanol provides the nitro benzodiazepine (XI), which is finally reduced with potassium formate and Pd/C in ethanol/water.

The regioselective reduction of 8-methyl-5-(4-nitrophenyl)-9H-1,3-dioxolo[4,5-h][2,3]benzodiazepine (I) with borane-THF complex catalyzed by (R)-2-amino-3-methyl-1,1-diphenyl-1-butanol (II) in dichloromethane gives the 8(R)-methyl derivative (III), which is acetylated with acetic anhydride yielding the 7-acetyl-8(R)-methyl derivative (IV). Finally, the nitro group of (IV) is reduced with hydrazine and Ni-Raney in methanol.

The regioselective reduction of 8-methyl-5-(4-nitrophenyl)-9H-1,3-dioxolo[4,5-h][2,3]benzodiazepine (I) with borane-THF complex catalyzed by (R)-2-amino-3-methyl-1,1-diphenyl-1-butanol (II) in dichloromethane gives the 8(R)-methyl derivative (III), which is acetylated with acetic anhydride yielding the 7-acetyl-8(R)-methyl derivative (IV). Finally, the nitro group of (IV) is reduced with hydrazine and Ni-Raney in methanol.

The reaction of 5-bromo-1,3-benzodioxole (I) with (S)-(-)-propylene oxide (II) by means of sec-butyllithium in THF gives the (S)-isopropanol derivative (IV) (also obtained by stereoselective reduction of 1-(1,3-benzodioxol-5-yl)-2-propanone (III) with Z. rouxii ATCC 14462 in a phosphate buffer). The cyclization of (IV) with 4-nitrobenzaldehyde (V) by means of HCl in hot toluene yields the benzopyran (VI), which is oxidized with air in aqueous NaOH affording the carbinol (VII). The reaction of (VII) with acetohydrazide (VIII) and HCl in refluxing ethanol gives the acetyl hydrazone (IX), which is mesylated at the secondary OH group with methanesulfonyl chloride and TEA in dichloromethane yielding the mesylate (X). The cyclization of (X) by means of NaOH in methanol provides the nitro benzodiazepine (XI), which is finally reduced with potassium formate and Pd/C in ethanol/water.

The reaction of 5-bromo-1,3-benzodioxole (I) with (S)-(-)-propylene oxide (II) by means of sec-butyllithium in THF gives the (S)-isopropanol derivative (IV) (also obtained by stereoselective reduction of 1-(1,3-benzodioxol-5-yl)-2-propanone (III) with Z. rouxii ATCC 14462 in a phosphate buffer). The cyclization of (IV) with 4-nitrobenzaldehyde (V) by means of HCl in hot toluene yields the benzopyran (VI), which is oxidized with air in aqueous NaOH affording the carbinol (VII). The reaction of (VII) with acetohydrazide (VIII) and HCl in refluxing ethanol gives the acetyl hydrazone (IX), which is mesylated at the secondary OH group with methanesulfonyl chloride and TEA in dichloromethane yielding the mesylate (X). The cyclization of (X) by means of NaOH in methanol provides the nitro benzodiazepine (XI), which is finally reduced with potassium formate and Pd/C in ethanol/water.

The reaction of 5-bromo-1,3-benzodioxole (I) with (S)-(-)-propylene oxide (II) by means of sec-butyllithium in THF gives the (S)-isopropanol derivative (IV) (also obtained by stereoselective reduction of 1-(1,3-benzodioxol-5-yl)-2-propanone (III) with Z. rouxii ATCC 14462 in a phosphate buffer). The cyclization of (IV) with 4-nitrobenzaldehyde (V) by means of HCl in hot toluene yields the benzopyran (VI), which is oxidized with air in aqueous NaOH affording the carbinol (VII). The reaction of (VII) with acetohydrazide (VIII) and HCl in refluxing ethanol gives the acetyl hydrazone (IX), which is mesylated at the secondary OH group with methanesulfonyl chloride and TEA in dichloromethane yielding the mesylate (X). The cyclization of (X) by means of NaOH in methanol provides the nitro benzodiazepine (XI), which is finally reduced with potassium formate and Pd/C in ethanol/water.

The regioselective reduction of 8-methyl-5-(4-nitrophenyl)-9H-1,3-dioxolo[4,5-h][2,3]benzodiazepine (I) with borane-THF complex catalyzed by (R)-2-amino-3-methyl-1,1-diphenyl-1-butanol (II) in dichloromethane gives the 8(R)-methyl derivative (III), which is acetylated with acetic anhydride yielding the 7-acetyl-8(R)-methyl derivative (IV). Finally, the nitro group of (IV) is reduced with hydrazine and Ni-Raney in methanol.

The reaction of 5-bromo-1,3-benzodioxole (I) with (S)-(-)-propylene oxide (II) by means of sec-butyllithium in THF gives the (S)-isopropanol derivative (IV) (also obtained by stereoselective reduction of 1-(1,3-benzodioxol-5-yl)-2-propanone (III) with Z. rouxii ATCC 14462 in a phosphate buffer). The cyclization of (IV) with 4-nitrobenzaldehyde (V) by means of HCl in hot toluene yields the benzopyran (VI), which is oxidized with air in aqueous NaOH affording the carbinol (VII). The reaction of (VII) with acetohydrazide (VIII) and HCl in refluxing ethanol gives the acetyl hydrazone (IX), which is mesylated at the secondary OH group with methanesulfonyl chloride and TEA in dichloromethane yielding the mesylate (X). The cyclization of (X) by means of NaOH in methanol provides the nitro benzodiazepine (XI), which is finally reduced with potassium formate and Pd/C in ethanol/water.

The reaction of 5-bromo-1,3-benzodioxole (I) with (S)-(-)-propylene oxide (II) by means of sec-butyllithium in THF gives the (S)-isopropanol derivative (IV) (also obtained by stereoselective reduction of 1-(1,3-benzodioxol-5-yl)-2-propanone (III) with Z. rouxii ATCC 14462 in a phosphate buffer). The cyclization of (IV) with 4-nitrobenzaldehyde (V) by means of HCl in hot toluene yields the benzopyran (VI), which is oxidized with air in aqueous NaOH affording the carbinol (VII). The reaction of (VII) with acetohydrazide (VIII) and HCl in refluxing ethanol gives the acetyl hydrazone (IX), which is mesylated at the secondary OH group with methanesulfonyl chloride and TEA in dichloromethane yielding the mesylate (X). The cyclization of (X) by means of NaOH in methanol provides the nitro benzodiazepine (XI), which is finally reduced with potassium formate and Pd/C in ethanol/water.

The regioselective reduction of 8-methyl-5-(4-nitrophenyl)-9H-1,3-dioxolo[4,5-h][2,3]benzodiazepine (I) with borane-THF complex catalyzed by (R)-2-amino-3-methyl-1,1-diphenyl-1-butanol (II) in dichloromethane gives the 8(R)-methyl derivative (III), which is acetylated with acetic anhydride yielding the 7-acetyl-8(R)-methyl derivative (IV). Finally, the nitro group of (IV) is reduced with hydrazine and Ni-Raney in methanol.

The reaction of 5-bromo-1,3-benzodioxole (I) with (S)-(-)-propylene oxide (II) by means of sec-butyllithium in THF gives the (S)-isopropanol derivative (IV) (also obtained by stereoselective reduction of 1-(1,3-benzodioxol-5-yl)-2-propanone (III) with Z. rouxii ATCC 14462 in a phosphate buffer). The cyclization of (IV) with 4-nitrobenzaldehyde (V) by means of HCl in hot toluene yields the benzopyran (VI), which is oxidized with air in aqueous NaOH affording the carbinol (VII). The reaction of (VII) with acetohydrazide (VIII) and HCl in refluxing ethanol gives the acetyl hydrazone (IX), which is mesylated at the secondary OH group with methanesulfonyl chloride and TEA in dichloromethane yielding the mesylate (X). The cyclization of (X) by means of NaOH in methanol provides the nitro benzodiazepine (XI), which is finally reduced with potassium formate and Pd/C in ethanol/water.