Condensation of 2'-amino-5'-chloro-2,2,2-trifluoroacetophenone (I) with trimethylsilyl isocyanate in the presence of dimethylaminopyridine, followed by desilylation with tetrabutylammonium fluoride provided the quinazoline derivative (II). Dehydration of the tertiary alcohol of (II) to afford imine (III) was carried out employing molecular sieves in refluxing toluene. Subsequent addition of lithium cyclopropylacetylide (IV) to (III) in the presence of BF3-Et2O yielded the racemic adduct (V). The desired (S)-enantiomer was finally isolated by means of chiral HPLC.
Condensation of 6'-amino-2,2,2,2',3'-pentafluoroacetophenone (I) with trimethylsilyl isocyanate in the presence of dimethylaminopyridine, followed by desilylation with tetrabutylammonium fluoride provided the quinazoline derivative (II). Dehydration of the tertiary alcohol of (II) to afford imine (III) was carried out employing molecular sieves in refluxing xylene. Subsequent addition of lithium cyclopropylacetylide (IV) to (III) in the presence of BF3-Et2O yielded the racemic adduct (V). The desired (S)-enantiomer was isolated by means of chiral HPLC.
Condensation of 2'-amino-5'-chloro-2,2,2-trifluoroacetophenone (I) with trimethylsilyl isocyanate in the presence of dimethylaminopyridine, followed by desilylation with tetrabutylammonium fluoride provided the quinazoline derivative (II). Dehydration of the tertiary alcohol of (II) to afford imine (III) was carried out employing molecular sieves in refluxing toluene. Subsequent addition of lithium cyclopropylacetylide (IV) to (III) in the presence of BF3-Et2O yielded the racemic adduct (V). The desired (S)-enantiomer (VI) was then isolated by means of chiral HPLC. Finally, reduction of the triple bond of (VI) with LiAlH4 furnished the corresponding olefin.
DPC-083 is directly obtained by reduction of (?-6-chloro-4(S)-(2-cyclopropylethynyl)-4-(trifluoromethyl)-3,4-dihydro-1H-quinazolin-2-one (I), DPC-961, with lithium aluminum hydride in 1,2-dichlorobenzene/THF.
DPC-961 (I) can be obtained by several different related ways: 1) Condensation of 2'-amino-5'-chloro-2,2,2-trifluoroacetophenone (II) with trimethylsilyl isocyanate in the presence of dimethylaminopyridine in THF, followed by desilylation with tetrabutylammonium fluoride in THF, provides the quinazoline derivative (III), which is dehydrated employing molecular sieves in refluxing toluene to yield the imine (IV). Treatment of compound (IV) with lithium cyclopropylacetylide (V) in THF in the presence of BF3.Et2O gives the racemic adduct (VI). Finally, the desired (S)-enantiomer (I) is isolated by means of chiral HPLC . 2) Condensation of 6-chloro-4-(trifluoromethyl)quinazolin-2(1H)-one (IV) with lithium cyclopropylacetylide (V) catalyzed by the chiral auxiliary (X) in toluene/THF gives directly DPC-961. The chiral auxiliary (X) can be synthesized as follows: Epoxidation of (+)-3-carene (VII) with MCPBA in dichloromethane gives the corresponding epoxide (VIII), which is then condensed with morpholine (IX) by means of MgBr2 as catalyst.
Condensation of 6'-amino-2,2,2,2',3'-pentafluoroacetophenone (I) with trimethylsilyl isocyanate in the presence of dimethylaminopyridine, followed by desilylation with tetrabutylammonium fluoride provided the quinazoline derivative (II). Dehydration of the tertiary alcohol of (II) to afford imine (III) was carried out employing molecular sieves in refluxing xylene. Subsequent addition of lithium cyclopropylacetylide (IV) to (III) in the presence of BF3-Et2O yielded the racemic adduct (V). The desired (S)-enantiomer (VI) was then isolated by means of chiral HPLC. Finally, reduction of the triple bond of (VI) with LiAlH4 furnished the corresponding olefin.