| Abstrakt: |
The Ritter reaction of cyano- and chlorocyanoacetylene with appropriate substrates provided a facile one step synthesis of 4,4-dimethyl-2-ethynyloxazoline (5), 4,4,6-trimethyl-2-ethynyl (7) and -2-chloroethynyl-5,6-dihydro-1,3-oxazine (8), 5,5-dimethyl-3-isopropylidene-2-ethynyl- (10) and -2-chloroethynyl-1-pyrroline (11). On treatment with diazomethane, 7gave 4,4,6-trimethyl-2-(4-1H-pyrazolyl)- (13) and -2-(3-1H-pyrazolyl)-5,6-dihydro-1,3-oxazine (14) in 42 and 40% yields respectively, while 8afforded only 4,4,6-trimethyl-2-[3-(4-chloro-1-methyl)-pyrazolyl]-5,6-dihydro-1,3-oxazine (15) in 52% yield. On the other hand, 10gave 5,5-dimethyl-3-isopropylidene-2-(3-1H-pyrazolyl)-1-pyrroline (16) in 64% yield and 11, 5,5-dimethyl-3-isopropylidene-2-[3-(4-chloro-1-methyl)-pyrazolyl]-1-pyrroline (17) in 16% yield. |
