UNSATURATED NITROGEN-COMPOUNDS CONTAINING FLUORINE .17. THE REACTIONS OF 3,5-BIS(TRIFLUOROMETHYL)-1H-1,2,4-TRIAZOLE WITH ALKYNES, ALKENES AND DIAZOMETHANE, AND OF SODIUM 3,5-BIS(TRIFLUOROMETHYL)-1,2,4-TRIAZOLIDE WITH HALOGEN COMPOUNDS

Thermal reaction of 3,5-bis(trifluoromethyl)-1H-1,2,4-triazole (1) with the alkynes HC=CCO2Er (7) (120 degrees C), MeO(2)CC drop CCO(2)Me (8) (120 degrees C) and Me(3)SiC drop CSiMe(3) (9) (150 degrees C) gave the following products where R=CF3C=NC(CF3)=NN-: 7 --> (E)-RCH=CHCO(2)Et (13a) (46%)+(Z)-RCH=CHCO(2)Et (13b) (49%); 8 --> (E)- or (Z)-MeO(2)CCR=CHCO(2)Me (14) (82%); 9 --> (E)-RCH=CHSiMe(3) (15) (37%) +(Z)-Me(3)SiCR=CHSiMe(3) (16b) (22%). The former two reactions involved nucleophilic attack by triazole 1 on the alkynes, while the latter reaction probably involved protodesilylation of alkyne 9 to afford HC drop CSiMe(3) (23) and electrophilic addition of triazole 1 to both alkynes 9 and 23. EIectrophilic addition of triazole 1 to the alkenes CH2=CHOEt (10) (20 degrees C) and norbornadiene (11) (70 degrees C) afforded the adduct RCHMeOEt 17 (81%) and the exo-norborn-5-ene 18 (92%), respectively, while reaction with diazomethane (12) gave the 1-methyl-1H-1,2,4-triazole (19) (92%). Treatment of triazole 1 with an equivalent amount of sodium hydride in solvent (Et(2)O, MeCN or THF) afforded the corresponding sodium triazolide (6), which on reaction in situ with halogen compounds gave the following products: EtO(2)CCH(2)Br (29) (in Et(2)O/EtOH) --> RCH(2)CO(2)Et (35) (87%); (n)BuBr (30) (in MeCN) --> R(n)Bu (36) (84%); CH2=CHCH2Cl (13) (in MeCN) --> RCH(2)CH=CH2 (37) (89%); CH2=CHCH2CH2Br (32) (in MeCN) --> RCH(2)CH(2)CH=CH2 (38) (92%); HC drop CCH2Br (33) (reflux for 8 h in MeCN) --> RCH(2)C drop CH (40) (74%); 33 (reflux for 6 d in MeCN) --> RCH=C=CH2 (39) (93%); pentafluoropyridine (34) (in MeCN) --> 4-RC(5)F(4)N (41) (78%); 34 (in THF) --> 41 (19%)+2RC(2)F(4)N (42) (5%)+2,4-R(2)C(5)F(5)N (43) (6%).