Dimethylformamide → 3,4-dihydro-8-methyl-7-[2-[4-(7-methyl-1,2-benzisoxazol-3-yl)-1-piperazinyl]ethyl]-2H,6H-pyrimido[2,1-b][1,3]-thiazin-6-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 7.4 parts of 7-(2-bromoethyl)-3,4-dihydro-8-methyl-2H,6H-pyrimido[2,1-b][1,3]thiazin-6-one monohydrobromide, 4.4 parts of 7-methyl-3-(1-piperazinyl)-1,2-benzisoxazole, 10 parts of sodium carbonate and 94 parts of N,N-dimethylformamide was stirred overnight at 90° C. After cooling, the reaction mixture was poured into water and the product was extracted with 4-methyl-2-pentanone. The extract was dried, filtered and evaporated. The residue was purified by column chromatography over silica gel using a mixture of trichloromethane and methanol (95:5 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from 4-methyl-2-pentanone. The product was filtered off and dried, yielding 3.8 parts (44.6%) of 3,4-dihydro-8-methyl-7-[2-[4-(7-methyl-1,2-benzisoxazol-3-yl)-1-piperazinyl]ethyl]-2H,6H-pyrimido[2,1-b][1,3]-thiazin-6-one; mp. 170.0° C. (compound 2).

Provenance & Evidence