Diels-alder adducts of dihydro-nitrogen heterocyclic phosphoramidates

A Diels-Alder Adduct of a dihydro-nitrogen heterocyclic phosphoramidate of the formula ##STR21## with a dienophile where ##STR22## represents a 1,2-dihydro-2-R-pyridinyl or lower alkyl substituted 1,2-dihydro-2-R-pyridinyl, R and R.sub.1 are lower alkyl or phenyl and X is O or S, said dienophile being of the formula

• Ch.sub.2 = cha, where A represents CHO, CO.sub.2 H, CO.sub.2 CH.sub.3, CO.sub.2 C.sub.2 H.sub.5, COCl, COCH.sub.3, COC.sub.6 H.sub.5, CN, NO.sub.2, C.sub.6 H.sub.5, CH.sub.2 OH, CH.sub.2 Z, CH.sub.2 NH.sub.2, CH.sub.2 CN, CH.sub.2 CO.sub.2 H, CH.sub.2 NCS, OCOCH.sub.3, SC.sub.6 H.sub.4 CH.sub.3, Z or H,
• C.sub.6 h.sub.5 ch = cha, where A represents CHO, CO.sub.2 H, CO.sub.2 CH.sub.3, CO.sub.2 C.sub.2 H.sub.5, COCH.sub.3, COC.sub.6 H.sub.5,
• Ch.sub.2 = ca.sub.2, where A represents CO.sub.2 C.sub.2 H.sub.5, CN, COCH.sub.3, Z,
• Ach = cha, where A represents CO.sub.2 H, COCl, CO.sub.2 CH.sub.3, CO.sub.2 C.sub.2 H.sub.5, COCH.sub.3, COC.sub.6 H.sub.5, Z, Quinone,
• Ac .tbd. ca, where A represents CO.sub.2 H, CO.sub.2 CH.sub.3, CO.sub.2 C.sub.2 H.sub.5,COC.sub.6 H.sub.5, C.sub.6 H.sub.5, H,
• and where Z represents halogen, or said dienophile is crotonaldehyde, dibenzalacetone, 1-cyclopentene-3-one, 1-cyclohexene-3-one, crotonic acid, crotonyl chloride, 3,4-dihydro-1-naphthoic acid, coumarin, beta-naphthol (as keto tautomer), cyclopentadiene, 1,3-cyclohexadiene, acenaphthylene, 4-vinyl-1-cyclohexene, 1-methyl-1-cyclopentene, dicyclopentadiene, maleic anhydride, or N-phenyl maleimide, and where said Diels-Alder Adduct is characterized by having the following structure in the adduct ##STR23## the carbons C.sub.1 and C.sub.2 being carbons of an unsaturated carbon to carbon bond of said dienophile and the atoms of the 6 membered ring of said structure containing nitrogen and the indicated double bond being the atoms of the 1,2-dihydropyridine group and the free valences of said structure being attached to atoms of said Diels-Alder Adduct.