Structure of a potential cross-linking reagent: 2,2'-bis(methoxymethylene)-2,2'-sulfonyldiacetonitrile (MMSBA).

The title compound (I) was prepared as a potential cross-linking reagent for nucleic acids and/or proteins. The compound is a stable, but reactive, crystalline solid which can be stored indefinitely upon adequate protection. The reagent reacts with amine nucleophiles - primary, secondary as well as heterocyclic - to afford bis-enamines. C8H8N2O4S, Mr = 228.23, monoclinic, C2/c, a = 18.031 (5), b = 9.372 (3), c = 13.455 (6) A, beta = 108.08 (5) degrees, V = 2161 (1) A3, Z = 8, Dx = 1.40 g cm-3, lambda(Mo K alpha) = 0.71069 A, mu = 2.81 cm1, F(000) = 944, T = 295 K. Final R = 0.041 for 1033 observed reflections. The bond distances in (I) are: S-O, 1.424 (3); S-C, 1.737 (4); C-CN, 1.417 (5); C=C, 1.342 (5); = C(H)-O, 1.295 (4); and C identical to N, 1.138 (5) A. The diagonal distance, alpha-alpha', between the two trans C atoms is 4.976 A.