Reaction #76614

Reaction equation

(8-chloro-1-methyl-1,2,3,4-tetrahydrobenzo[e][1,4]diazepin-5-ylidenemethyl)phosphonic acid diethyl ester

phenylboronic acid

caesium fluoride

→

(1-methyl-8-phenyl-1,2,3,4-tetrahydro-benzo[e][1,4]diazepin-5-ylidenemethyl)phosphonic acid diethyl ester

Yield 70.8%

Solvents

dioxane

Conditions

Workup

1. 1
   OtherThe mixture was purified by column chromatography (20 g IST pre-packed column)
2. 2
   Washeluting with acetone—petroleum ether (40-60° C.) (1:2)

Procedure

To 286 mg (0.83 mmol) of (8-chloro-1-methyl-1,2,3,4-tetrahydrobenzo[e][1,4]diazepin-5-ylidenemethyl)phosphonic acid diethyl ester (prepared as described in Example 48) in 1 ml of dioxane was added 106 mg (0.87 mmol) of phenylboronic acid, 8.4 mg (0.03 mmol) of tricyclohexylphosphine, 11.5 mg 0.013 mmol)of tris-(dibenzylideneacetone)-palladium (0) and 152 mg of caesium fluoride. The mixture was heated at 80° C. for 14 hours. The mixture was purified by column chromatography (20 g IST pre-packed column) eluting with acetone—petroleum ether (40-60° C.) (1:2) to give 227 mg of (1-methyl-8-phenyl-1,2,3,4-tetrahydro-benzo[e][1,4]diazepin-5-ylidenemethyl)phosphonic acid diethyl ester as a yellow oil; MS: m/e 387 [M+H]+.

Source