2-(2-methyl-4-nitrophenylimino)-4,4-dimethyl-1,3-thiazolidine was prepared in a manner analogous to that described in Method C1a. To a suspension of 2-(2-methyl-4-nitrophenylimino)-4,4-dimethyl-1,3-thiazolidine (1.5 mmol) in toluene (10 mL) was added 2-methylprop-2-en-1-yl bromide (4.5 mmol) and the reaction mixture was heated at the reflux temp. for 3 h at which time the reaction was judged complete by TLC. The resulting precipitate was filtered at 50 ° C. The collected solids were washed with toluene (20 mL) and CH2Cl2 (20 mL) to yield 2-(2-methyl-4-nitrophenylimino)-3-(2-methyl-prop-2-enyl)-4,4-dimethyl-1,3-thiazolidine HBr salt (1.14 g, 77%): mp 229° C.
