Substituted pyrrolo[2,3-b]pyrazines as ATR kinase inhibitors

A compound of formula I:

• or a pharmaceutically acceptable salt thereof wherein:
• R1 is halo, CN, NO2, X, Q1, or X-Q1;
• X is C1-10alkyl wherein up to two methylene units of said C1-10alkyl is optionally replaced with —O—, —S—, or —NR*—;
• and wherein X is optionally substituted with 1-2 occurrences of JX;
• Q1 is a 3-8 membered monocyclic aromatic or nonaromatic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• and wherein Q1 is optionally substituted with 0-2 occurrences of JQ1;
• JX is halo, CN, C1-3alkyl, OH, O(C1-3alkyl), NH2, NH(C1-3alkyl), or N(C1-3alkyl)2;
• JQ1 is C1-6alkyl wherein up to one methylene unit of said C1-6alkyl is optionally replaced with —O—, —S—, or —NR*—;
• Q is a 5-6 membered monocyclic aromatic or nonaromatic ring having 0-4 heteroatoms independently selected from nitrogen, oxygen, or sulfur;
• J is H, halo, ═O, CN, V1, (V)t—R2, or
• each V and V1 is independently a C1-10aliphatic group wherein up to 3 methylene units are optionally replaced with O, NR″, C(O), S, S(O), or S(O)2;
• wherein said C1-10aliphatic group is optionally substituted with 1-3 occurrences of halo or CN;
• R2 is a 3-7 membered aromatic or nonaromatic monocyclic ring having 0-3 heteroatoms selected from the group consisting of oxygen, nitrogen, and sulfur;
• and wherein R2 is optionally substituted with 1-3 occurrences of halo, ═O, CN, C3-6cycloalkyl, or C1-10aliphatic;
• wherein up to 3 methylene units of said C1-10aliphatic are optionally replaced with NR′, O, S, or CO;
• J1 is halo, CN, or C1-2aliphatic wherein up to one methylene unit is optionally replaced with O, NR+, or S;
• Ja is H or C1-6alkyl;
• Jb is C1-6alkyl;
• or Ja and Jb join together to form a 3-7 membered monocyclic saturated ring having 0-2 heteroatoms selected from the group consisting of oxygen, nitrogen, and sulfur;
• wherein said monocyclic saturated ring is optionally substituted with 1-2 occurrences of halo or C1-3alkyl;
• Jc is CN or L-Z;
• L is C(O), S(O)2, or C(O)NR+;
• Z is (U)r-Q2 or C1-6alkyl wherein 0-2 methylene units of said C1-6alkyl are replaced with O or NR+;
• U is C1-2alkyl;
• Q2 is C3-6cycloalkyl or 4-6 membered saturated or partially saturated heterocyclyl having 1-2 heteroatoms selected from the group consisting of oxygen, nitrogen, and sulfur;
• R3 is H, halo, CN, or C1-3alkyl wherein up to one methylene unit of said C1-3alkyl is optionally replaced with O, NH, or S;
• and wherein said C1-3alkyl is optionally and independently substituted with 1-3 occurrences of halo or OH;
• q, r, n, and t are each independently 0 or 1;
• p is 0, 1, 2, 3, or 4;
• and
• each R, R′, R″, R+, and R* is independently H or C1-4alkyl wherein said C1-4alkyl is optionally substituted with 1-4 halo.